def parse_not_blank(val, allow_blank: false)
      return if val.nil? || !allow_blank && val.is_a?(String) && val.blank?
      yield(val)
    end
def parse_not_blank(val, allow_blank: false)
      return if val.nil? || !allow_blank && val.is_a?(String) && val.blank?
      yield(val)
    end
Parses value with given block only when it is not nil.
 Empty string is converted to nil. Pass `allow_blank: true` to return it as is.