NAME
    previous_object - give object that called current object

    SYNOPSIS
    object previous_object()

    DESCRIPTION
    This function returns the previous object that called a function in this object from the outside, ie with `call_other()'.

    This include `call_other(this_object(), ...)' constructions. In this case, the returned value will be `this_object()'.

    CAVEAT
    If the function was called internally, the result is undefined.