Warning: This function is
EXPERIMENTAL. The behaviour of this function, the
name of this function, and anything else documented about this
function may change without notice in a future release of PHP.
Use this function at your own risk.
Test to see if the property corresponds to a containment relationship.
Returns TRUE
if the property defines a containment relationship,
or FALSE
if it is reference.
Return Values
Returns TRUE
if the property defines a containment relationship,
or FALSE
if it is reference.