The Requires.Directive class creates objects which represent the
::REQUIRES directives of an ooRexx program.
Superclass: Rexx.Directive
Returns the name of the required program, as a string element or a symbol element.
Returns the namespace associated with this ::REQUIRES
directive, as a symbol element, or .Nil when the
NAMESPACE keyword was not specified.
Returns 1 when the LIBRARY keyword was
specified on the directive, otherwise returns .Nil.