Action node class. The namespace is used to distinguish actions with the
same simple name.
Although this class has a namespace attribute the equality of
two ActionNodes can still be determined by comparing their
URIs. Therefore this class does not override equals(Object)
from ObjectNode.
namespaceattribute the equality of twoActionNodes can still be determined by comparing their URIs. Therefore this class does not overrideequals(Object)fromObjectNode.