getOtherAttributes() Gets a map that contains attributes that aren't bound to any typed property on this class.
the map is keyed by the name of the attribute and
the value is the string value of the attribute.
the map returned by this method is live, and you can add new attribute
by updating the map directly.
Gets a map that contains attributes that aren't bound to any typed property on this class.
the map is keyed by the name of the attribute and
the value is the string value of the attribute.
the map returned by this method is live, and you can add new attribute
by updating the map directly. Because of this design, there's no setter.
always non-null