anchor.diff:      :  code=ll1statement
       |  (functioncallStatNoAssign) => code=functioncallStatNoAssign
       |   (functioncallStatAssignManyReturnParam) => code=functioncallStatAssignManyReturnParam
  +    |   (functioncallStatAssignOneReturnParamAsDecl) => code=functioncallStatAssignOneReturnParamAsDecl
       |  (predictAssignStat) => code=assignStat
       ;
   
  
positive.code: functioncallStatAssignOneReturnParamAsDecl returns [StringTemplate code=template("call")]
  {StringTemplate f=null;}
      :
          f= singleReturnParameter { code.setAttribute("outputs", f); }
          ASSIGN
          functionInvocation[code]
      ;
  
negative.code: functioncallStatAssignOneReturnParamAsAssign returns [StringTemplate code=template("call")]
  {StringTemplate f=null;}
      :
          f= singleReturnParameterNoType { code.setAttribute("outputs", f); }
          ASSIGN
          functionInvocation[code]
      ;
  