anchor.diff:    String get includePath => _sassOptionGetIncludePath(_handle);
     String get sourceMapFile => _sassOptionGetSourceMapFile(_handle);
   
  -  void set precision(int precision) => _sassOptionSetPrecision(_handle, precision);
  -  void set outputStyle(int outputStyle) => _sassOptionSetOutputStyle(_handle, outputStyle);
  -  void set sourceComments(bool sourceComments) => _sassOptionSetSourceComments(_handle, sourceComments);
  -  void set sourceMapEmbed(bool sourceMapEmbed) => _sassOptionSetSourceMapEmbed(_handle, sourceMapEmbed);
  -  void set sourceMapContents(bool sourceMapContents) => _sassOptionSetSourceMapContents(_handle, sourceMapContents);
  -  void set omitSourceMapUrl(bool omitSourceMapUrl) => _sassOptionSetOmitSourceMapUrl(_handle, omitSourceMapUrl);
  -  void set isIndentedSyntaxSrc(bool isIndentedSyntaxSrc) => _sassOptionSetIsIndentedSyntaxSrc(_handle, isIndentedSyntaxSrc);
  -  void set inputPath(String inputPath) => _sassOptionSetInputPath(_handle, inputPath);
  -  void set outputPath(String outputPath) => _sassOptionSetOutputPath(_handle, outputPath);
  -  void set includePath(String includePath) => _sassOptionSetIncludePath(_handle, includePath);
  -  void set sourceMapFile(String sourceMapFile) => _sassOptionSetSourceMapFile(_handle, sourceMapFile);
  +  void set precision(int precision) =>
  +      _sassOptionSetPrecision(_handle, precision);
  +  void set outputStyle(int outputStyle) =>
  +      _sassOptionSetOutputStyle(_handle, outputStyle);
  +  void set sourceComments(bool sourceComments) =>
  +      _sassOptionSetSourceComments(_handle, sourceComments);
  +  void set sourceMapEmbed(bool sourceMapEmbed) =>
  +      _sassOptionSetSourceMapEmbed(_handle, sourceMapEmbed);
  +  void set sourceMapContents(bool sourceMapContents) =>
  +      _sassOptionSetSourceMapContents(_handle, sourceMapContents);
  +  void set omitSourceMapUrl(bool omitSourceMapUrl) =>
  +      _sassOptionSetOmitSourceMapUrl(_handle, omitSourceMapUrl);
  +  void set isIndentedSyntaxSrc(bool isIndentedSyntaxSrc) =>
  +      _sassOptionSetIsIndentedSyntaxSrc(_handle, isIndentedSyntaxSrc);
  +  void set inputPath(String inputPath) =>
  +      _sassOptionSetInputPath(_handle, inputPath);
  +  void set outputPath(String outputPath) =>
  +      _sassOptionSetOutputPath(_handle, outputPath);
  +  void set includePath(String includePath) =>
  +      _sassOptionSetIncludePath(_handle, includePath);
  +  void set sourceMapFile(String sourceMapFile) =>
  +      _sassOptionSetSourceMapFile(_handle, sourceMapFile);
   
     // Native functions
     int _sassMakeOptions() native "sass_make_options";
     void _peerRegister(Object object, int handle) native "peer_register";
   
     int _sassOptionGetPrecision(int handle) native "sass_option_get_precision";
  -  int _sassOptionGetOutputStyle(int handle) native "sass_option_get_output_style";
  -  bool _sassOptionGetSourceComments(int handle) native "sass_option_get_source_comments";
  -  bool _sassOptionGetSourceMapEmbed(int handle) native "sass_option_get_source_map_embed";
  -  bool _sassOptionGetSourceMapContents(int handle) native "sass_option_get_source_map_contents";
  -  bool _sassOptionGetOmitSourceMapUrl(int handle) native "sass_option_get_omit_source_map_url";
  -  bool _sassOptionGetIsIndentedSyntaxSrc(int handle) native "sass_option_get_is_indented_syntax_src";
  -  String _sassOptionGetInputPath(int handle) native "sass_option_get_input_path";
  -  String _sassOptionGetOutputPath(int handle) native "sass_option_get_output_path";
  -  String _sassOptionGetIncludePath(int handle) native "sass_option_get_include_path";
  -  String _sassOptionGetSourceMapFile(int handle) native "sass_option_get_source_map_file";
  +  int _sassOptionGetOutputStyle(int handle) native
  +      "sass_option_get_output_style";
  +  bool _sassOptionGetSourceComments(int handle) native
  +      "sass_option_get_source_comments";
  +  bool _sassOptionGetSourceMapEmbed(int handle) native
  +      "sass_option_get_source_map_embed";
  +  bool _sassOptionGetSourceMapContents(int handle) native
  +      "sass_option_get_source_map_contents";
  +  bool _sassOptionGetOmitSourceMapUrl(int handle) native
  +      "sass_option_get_omit_source_map_url";
  +  bool _sassOptionGetIsIndentedSyntaxSrc(int handle) native
  +      "sass_option_get_is_indented_syntax_src";
  +  String _sassOptionGetInputPath(int handle) native
  +      "sass_option_get_input_path";
  +  String _sassOptionGetOutputPath(int handle) native
  +      "sass_option_get_output_path";
  +  String _sassOptionGetIncludePath(int handle) native
  +      "sass_option_get_include_path";
  +  String _sassOptionGetSourceMapFile(int handle) native
  +      "sass_option_get_source_map_file";
   
  -  void _sassOptionSetPrecision(int handle, int precision) native "sass_option_set_precision";
  -  void _sassOptionSetOutputStyle(int handle, int outputStyle) native "sass_option_set_output_style";
  -  void _sassOptionSetSourceComments(int handle, bool sourceComments) native "sass_option_set_source_comments";
  -  void _sassOptionSetSourceMapEmbed(int handle, bool sourceMapEmbed) native "sass_option_set_source_map_embed";
  -  void _sassOptionSetSourceMapContents(int handle, bool sourceMapContents) native "sass_option_set_source_map_contents";
  -  void _sassOptionSetOmitSourceMapUrl(int handle, bool omitSourceMapUrl) native "sass_option_set_omit_source_map_url";
  -  void _sassOptionSetIsIndentedSyntaxSrc(int handle, bool isIndentedSyntaxSrc) native "sass_option_set_is_indented_syntax_src";
  -  void _sassOptionSetInputPath(int handle, String inputPath) native "sass_option_set_input_path";
  -  void _sassOptionSetOutputPath(int handle, String outputPath) native "sass_option_set_output_path";
  -  void _sassOptionSetIncludePath(int handle, String includePath) native "sass_option_set_include_path";
  -  void _sassOptionSetSourceMapFile(int handle, String sourceMapFile) native "sass_option_set_source_map_file";
  +  void _sassOptionSetPrecision(int handle, int precision) native
  +      "sass_option_set_precision";
  +  void _sassOptionSetOutputStyle(int handle, int outputStyle) native
  +      "sass_option_set_output_style";
  +  void _sassOptionSetSourceComments(int handle, bool sourceComments) native
  +      "sass_option_set_source_comments";
  +  void _sassOptionSetSourceMapEmbed(int handle, bool sourceMapEmbed) native
  +      "sass_option_set_source_map_embed";
  +  void _sassOptionSetSourceMapContents(int handle,
  +      bool sourceMapContents) native "sass_option_set_source_map_contents";
  +  void _sassOptionSetOmitSourceMapUrl(int handle, bool omitSourceMapUrl) native
  +      "sass_option_set_omit_source_map_url";
  +  void _sassOptionSetIsIndentedSyntaxSrc(int handle,
  +      bool isIndentedSyntaxSrc) native "sass_option_set_is_indented_syntax_src";
  +  void _sassOptionSetInputPath(int handle, String inputPath) native
  +      "sass_option_set_input_path";
  +  void _sassOptionSetOutputPath(int handle, String outputPath) native
  +      "sass_option_set_output_path";
  +  void _sassOptionSetIncludePath(int handle, String includePath) native
  +      "sass_option_set_include_path";
  +  void _sassOptionSetSourceMapFile(int handle, String sourceMapFile) native
  +      "sass_option_set_source_map_file";
   }
   
  -
  -class SassFileContext {
  +abstract class SassContext {
     int _handle;
     SassOptions _options;
  +
  +  int compile();
  +
  +  SassOptions get options => _options;
  +  void set options(SassOptions options);
  +
  +  String get outputString => _sassContextGetOutputString(_handle);
  +  String get errorJson => _sassContextGetErrorJson(_handle);
  +  String get sourceMapString => _sassContextGetSourceMapString(_handle);
  +  String get includedFiles => _sassContextGetIncludedFiles(_handle);
  +
  +  // Native functions
  +  void _peerRegister(Object object, int handle) native "peer_register";
  +
  +  String _sassContextGetOutputString(int handle) native
  +      "sass_context_get_output_string";
  +  String _sassContextGetErrorJson(int handle) native
  +      "sass_context_get_error_json";
  +  String _sassContextGetSourceMapString(int handle) native
  +      "sass_context_get_source_map_string";
  +  String _sassContextGetIncludedFiles(int handle) native
  +      "sass_context_get_included_files";
  +}
  +
  +class SassFileContext extends SassContext {
   
     SassFileContext(String inputPath) {
       _handle = _sassMakeFileContext(inputPath);
  
positive.code: 
    int compile() => _sassCompileDataContext(_handle);
  
    SassOptions get options => _options;
    void set options(SassOptions options) {
      _sassDataContextSetOptions(_handle, options.handle);
      _options = new SassOptions.fromHandle(_sassDataContextGetOptions(_handle));
    }
  
    String get outputString => _sassContextGetOutputString(_handle);
    String get errorJson => _sassContextGetErrorJson(_handle);
    String get sourceMapString => _sassContextGetSourceMapString(_handle);
    String get includedFiles => _sassContextGetIncludedFiles(_handle);
  
    // Native functions
    int _sassMakeDataContext(String sourceString) native "sass_make_data_context";
    void _peerRegister(Object object, int handle) native "peer_register";
  
    int _sassCompileDataContext(int handle) native "sass_compile_data_context";
  
    int _sassDataContextGetOptions(int handle) native "sass_data_context_get_options";
    void _sassDataContextSetOptions(int handle, int options) native "sass_data_context_set_options";
  
    String _sassContextGetOutputString(int handle) native "sass_context_get_output_string";
    String _sassContextGetErrorJson(int handle) native "sass_context_get_error_json";
    String _sassContextGetSourceMapString(int handle) native "sass_context_get_source_map_string";
    String _sassContextGetIncludedFiles(int handle) native "sass_context_get_included_files";
  }
  
negative.code: /// Dart class-based wrappers for the libsass C/C++ Sass compiler.
  ///
  /// This library implements the libsass C/C++ Sass compiler using Dart classes.
  /// The classes closely follow the functions laid out in the `sass_context.h`
  /// file in the original libsass library. For further documentation, please
  /// refer to the
  /// [libsass implementation guide](https://github.com/sass/libsass/wiki)
  library libsass;
  
  import 'dart-ext:sass_extension';
  
  abstract class Sass {
    /// The version of the compiled libsass C/C++ library.
    static String libsassVersion() native "libsass_version";
  }
  
  class SassOptions {
    int _handle;
  