def determine_type_from_string(string)
      if string =~ TYPE_FORMAT and const_defined?(string, *EXTRA_CONST_ARGS)
        const_get(string, *EXTRA_CONST_ARGS)
      end
    end
def determine_type_from_string(string)
      if string =~ TYPE_FORMAT and const_defined?(string, *EXTRA_CONST_ARGS)
        const_get(string, *EXTRA_CONST_ARGS)
      end
    end
Return the class given a string

 @param [String] string

 @return [Class]

 @return [nil]
   nil if the type cannot be determined by the string

 @api private