code: public static String getAlias(Function function) {
          String functionAlias = getStringProperty(function,Function.PROP_NAME);
          if(!functionAlias.isEmpty()) {
              return functionAlias;
          }
          return function.getClass().getSimpleName();
      }
docs: Return the alias name of the function
  @param function Function instance
  @return the function ALIAS, name of the function in SQL engine