code: public ExpressionBuilder notNull(final Object property, final String name) {
  
          if (property == null) {
              messageContainer.addErrorMessage("Property '" + name + "' cannot be null");
          }
  
          return this;
      }
docs: Adds a description for a null property.
  
  @param property The property to check.
  @param name     The property name.
  @return This object.