anchor.diff:  ID_NAME: HASH IDENTIFIER;
   CLASS_NAME: DOT IDENTIFIER;
   
  -import_target: URL | STRING;
  +string: DSTRING | SSTRING;
  +
  +import_target: URL | string;
   
   import_statement : IMPORT_KW
                      import_target ( ',' import_target )*
  
positive.code: //simple_selector_sequence: simple_selector+;
  
  //simple_selector: parser.cpp:426
  simple_selector: (ID_NAME | CLASS_NAME | STRING ) // or number
                   | type_selector // don't think this is right...
                   | negated_selector
                   | pseudo_selector
  
negative.code:                     ((EVEN_KW | ODD_KW)
                       | binomial
                       | IDENTIFIER
                       | string
                      )?
                    RPAREN
                   )
  