anchor.diff:  	;
   
   classBlock
  -	:	'{'!  (identifierDeclaration ';'!)* methodDeclaration* unittest* '}'!
  +	:	'{'!  (identifierDeclaration ';'!)* methodDefinition* unittest* '}'!
   	;
   
   interfaceBlock
  -  : '{'! methodDefinition* '}'!
  +  : '{'! methodDeclaration* '}'!
   	;
   
   test
  
positive.code:   : doc? modifiers? TypeIdentifier VariableIdentifier parameterList
    ;
  
  methodDefinition
    : methodSignature ';'
    -> ^(METHOD methodSignature)
    ;
  
negative.code: 	-> ^(IMPL qualifiedType)*
  	;
  
  interfaceDefinition
    : 'interface' TypeIdentifier interfaceBlock
    -> ^(INTERFACE TypeIdentifier interfaceBlock?)
    ;
  