code: public static AbstractType<?> getTypeByFunction(String functionName)
      {
          Function function;
  
          try
          {
              function = Function.valueOf(functionName.toUpperCase());
          }
          catch (IllegalArgumentException e)
          {
              String message = String.format("Function '%s' not found. Available functions: %s", functionName, Function.getFunctionNames());
              throw new RuntimeException(message, e);
          }
  
          return function.getValidator();
      }
docs: Get AbstractType by function name
  @param functionName - name of the function e.g. utf8, integer, long etc.
  @return AbstractType type corresponding to the function name