def extract_inclusion_values(klass, attribute)
      values = nil

      klass.validators_on(attribute).each do |validator|
        case validator
        when ActiveModel::Validations::InclusionValidator
          values = validator.options[:in]
        end
      end

      values
    end
def extract_inclusion_values(klass, attribute)
      values = nil

      klass.validators_on(attribute).each do |validator|
        case validator
        when ActiveModel::Validations::InclusionValidator
          values = validator.options[:in]
        end
      end

      values
    end
Returns [Array] list of inclusion values for this attribute.
 Returns nil when there are no inclusion values for this attribute.