code: public Criteria contains(Object o) {
          this.criteriaType = RelationalOperator.CONTAINS;
          this.right = ValueNode.toValueNode(o);
          return this;
      }
docs: The <code>contains</code> operator asserts that the provided object is contained
  in the result. The object that should contain the input can be either an object or a String.
  
  @param o that should exists in given collection or
  @return the criteria