code: function getSymbolsOfParameterPropertyDeclaration(parameter, parameterName) {
              var constructorDeclaration = parameter.parent;
              var classDeclaration = parameter.parent.parent;
              var parameterSymbol = getSymbol(constructorDeclaration.locals, parameterName, 107455 /* Value */);
              var propertySymbol = getSymbol(classDeclaration.symbol.members, parameterName, 107455 /* Value */);
              if (parameterSymbol && propertySymbol) {
                  return [parameterSymbol, propertySymbol];
              }
              ts.Debug.fail("There should exist two symbols, one as property declaration and one as parameter declaration");
          }
docs: Get symbols that represent parameter-property-declaration as parameter and as property declaration
  @param parameter a parameterDeclaration node
  @param parameterName a name of the parameter to get the symbols for.
  @return a tuple of two symbols