anchor.diff:  
     --omit-implicit-checks
       Omit implicit runtime checks, such as parameter checks and implicit
  -    downcasts. These checks are included by default in strong mode. By
  +    downcasts. These checks are included by default in Dart 2.0. By
       using this flag the checks are removed, however the compiler will assume
       that all such checks were valid and may use this information for
       optimizations. Use this option only if you have enough testing to ensure
  
positive.code:   --version
      Display version information.
  
    -p<path>, --package-root=<path>
      Where to find packages, that is, "package:..." imports.  This option cannot
      be used with --packages.
  
    --packages=<path>
      Path to the package resolution configuration file, which supplies a mapping
      of package names to paths.  This option cannot be used with --package-root.
  
    --analyze-all
      Analyze all code.  Without this option, the compiler only analyzes
      code that is reachable from [main].  This option implies --analyze-only.
  
    --analyze-only
      Analyze but do not generate code.
  
    --analyze-signatures-only
      Skip analysis of method bodies and field initializers. This option implies
      --analyze-only.
  
    --suppress-warnings
      Do not display any warnings.
  
  
negative.code: 
    Uri script = currentDirectory.resolve(arguments[0]);
    diagnosticHandler.autoReadFileUri = true;
    CompilerOptions compilerOptions = CompilerOptions.parse(options,
        libraryRoot: libraryRoot, platformBinaries: platformBinaries)
      ..entryPoint = script
  