def wf_ts?(timestamp)
      return true if timestamp.is_a?(Time) || timestamp.is_a?(Date)
      raise Wavefront::Exception::InvalidTimestamp
    end
def wf_ts?(timestamp)
      return true if timestamp.is_a?(Time) || timestamp.is_a?(Date)
      raise Wavefront::Exception::InvalidTimestamp
    end
Ensure the given argument is a valid timestamp

 @param timestamp [DateTime] the timestamp name to validate
 @return True if the value is valid
 @raise Wavefront::Exception::InvalidTimestamp