code: public Expression<String> in(String[] value) {
  		String listString = "";
  		Boolean firstString = true;
  		for (String v : value) {
  			if (firstString) {
  				listString = listString.concat("('").concat(v).concat("'");
  				firstString = false;
  			} else {
  				listString = listString.concat(", '").concat(v).concat("'");
  			}
  		}
  		listString = listString.concat(")");
  		return new Expression<String>(this, Operation.in, listString);
  	}
docs: Method to construct the in expression for string
  
  @param value the string array
  @return Expression