- * - Will return false if $that->getModel() != $this->getModel().
- * - Will return false if $that->getNativeData() is not equal to $this->getNativeData(),
- * where the meaning of "equal" depends on the actual data model.
+ * - Will return false if $that->getModel() !== $this->getModel().
+ * - Will return false if get_class( $that ) !== get_class( $this )
+ * - Should return false if $that->getModel() == $this->getModel() and
+ * $that is not semantically equivalent to $this, according to
+ * the data model defined by $this->getModel().