def validate_hash_arg(arg, parent, key, arg_type)
      arg_type = handle_xsi_type(arg, parent, key, arg_type)
      validate_arguments(arg, arg_type[:fields], arg_type[:ns])
    end
def validate_hash_arg(arg, parent, key, arg_type)
      arg_type = handle_xsi_type(arg, parent, key, arg_type)
      validate_arguments(arg, arg_type[:fields], arg_type[:ns])
    end
Validates Hash argument.