anchor.diff:  IdentifierPart
     : [a-zA-Z0-9$_] ;
   
  -StringLiteral
  +stringLiteral
  +  : StringLiteralFragment+ ;
  +
  +StringLiteralFragment
     : '"' DoubleQuotedStringCharacter* '"'
     | '\'' SingleQuotedStringCharacter* '\'' ;
   
  
positive.code: 
  stateVariableDeclaration
    : typeName
      ( PublicKeyword | InternalKeyword | PrivateKeyword | ConstantKeyword )*
      identifier ('=' expression)? ';' ;
  
  usingForDeclaration
    : 'using' identifier 'for' ('*' | typeName) ';' ;
  
negative.code: 
  eventParameter
    : typeName IndexedKeyword? identifier? ;
  
  variableDeclaration
    : typeName storageLocation? identifier ;
  