anchor.diff:    @override
     String toString() => _buf.toString();
     
  -}+}
  
positive.code: 
  /// TOML document builder.
  class TomlDocumentBuilder {
    
    /// A buffer which holds the textual representation of the document.
    final StringBuffer _buf = new StringBuffer();
  
negative.code:   
    /// Inserts a [key].
    void encodeKey(String key) {
      if(bareKeyRegExp.hasMatch(key)){
        _buf.write(key);
      }
      else{
        basicString(key);
      }
    }
    
    /// Applies a [TomlValueEncoder] on [value].
  