code: function isDigitSequence(sValue, oConstraints) {
  		return oConstraints && oConstraints.isDigitSequence && sValue && sValue.match(rDigitsOnly);
  	}
docs: Checks whether isDigitSequence constraint is set to true and the given value is a digit
  sequence.
  
  @param {string} [sValue]
  the value to be checked
  @param {object} [oConstraints]
  the currently used constraints
  @returns {boolean}
  true if isDigitSequence is set to true and the given value is a digit sequence