def check_report_definition_hash(report_definition)
      # Minimal set of fields required.
      REQUIRED_FIELDS.each do |field|
        unless report_definition.include?(field)
          raise AdwordsApi::Errors::InvalidReportDefinitionError,
              "Required field '%s' is missing in the definition" % field
        end
      end
      # Fields list is also required.
      unless report_definition[:selector].include?(:fields)
        raise AdwordsApi::Errors::InvalidReportDefinitionError,
            'Fields list is required'
      end
      # 'Fields' must be an Array.
      unless report_definition[:selector][:fields].kind_of?(Array)
        raise AdwordsApi::Errors::InvalidReportDefinitionError,
            'Fields list must be an array'
      end
      # We should request at least one field.
      if report_definition[:selector][:fields].empty?
        raise AdwordsApi::Errors::InvalidReportDefinitionError,
            'At least one field needs to be requested'
      end
    end
def check_report_definition_hash(report_definition)
      # Minimal set of fields required.
      REQUIRED_FIELDS.each do |field|
        unless report_definition.include?(field)
          raise AdwordsApi::Errors::InvalidReportDefinitionError,
              "Required field '%s' is missing in the definition" % field
        end
      end
      # Fields list is also required.
      unless report_definition[:selector].include?(:fields)
        raise AdwordsApi::Errors::InvalidReportDefinitionError,
            'Fields list is required'
      end
      # 'Fields' must be an Array.
      unless report_definition[:selector][:fields].kind_of?(Array)
        raise AdwordsApi::Errors::InvalidReportDefinitionError,
            'Fields list must be an array'
      end
      # We should request at least one field.
      if report_definition[:selector][:fields].empty?
        raise AdwordsApi::Errors::InvalidReportDefinitionError,
            'At least one field needs to be requested'
      end
    end
Checks if the report definition looks correct.