add_documents_property

Inserts/updates property on "properties" list in this.

Since, a GDataDocumentsProperty is uniquely identified by key and visibility, if no such property exists in the "properties" list, then a property will be appended to the list after incrementing the reference count.

In case that there already exists a property in "properties", the DocumentsProperty inside the list will be updated to property. Note that value has no role in determining the uniqueness of a DocumentsProperty.

The changes made by this function will be local only and you need to explicitly update this by calling update_entry.

Parameters:

this	a DocumentsEntry
property	a DocumentsProperty

Returns:

true if the property doesn't exist in the "properties" list, or that value of property has been set to null by a call to remove_documents_property. false if property exists in "properties" list, or in the case that this or property aren't of proper types.