def validate
      missing_parameters = []
      required_fields.each do |param|
        missing_parameters << param.to_s unless self.send(param)
      end
      raise RTurk::MissingParameters, "Parameters: '#{missing_parameters.join(', ')}'" unless missing_parameters.empty?
    end
def validate
      missing_parameters = []
      required_fields.each do |param|
        missing_parameters << param.to_s unless self.send(param)
      end
      raise RTurk::MissingParameters, "Parameters: '#{missing_parameters.join(', ')}'" unless missing_parameters.empty?
    end
More complicated validation run before request