Queries the item at position item_index in model for the attribute
specified by attribute.
If expected_type is non-NULL then it specifies the expected type of
the attribute. If it is NULL then any type will be accepted.
If the attribute exists and matches expected_type (or if the
expected type is unspecified) then the value is returned.
If the attribute does not exist, or does not match the expected type
then NULL is returned.
Since 2.32
Queries the item at position item_index in model for the attribute specified by attribute. If expected_type is non-NULL then it specifies the expected type of the attribute. If it is NULL then any type will be accepted. If the attribute exists and matches expected_type (or if the expected type is unspecified) then the value is returned. If the attribute does not exist, or does not match the expected type then NULL is returned. Since 2.32