Add suppport for InternalRelation in requirement.py

[ylussaud]

This can be done by adding the following class:

class InternalRelation(AbstractRelation):
    """
    """
    def __init__(self, java_object = None):
        """
        """
        if java_object is None:
            JavaObject.__init__(self, create_e_object("http://www.polarsys.org/kitalpha/requirements", "InternalRelation"))
        elif isinstance(java_object, InternalRelation):
            JavaObject.__init__(self, java_object.get_java_object())
        elif get_e_classifier("http://www.polarsys.org/kitalpha/requirements", "InternalRelation").isInstance(java_object):
            JavaObject.__init__(self, java_object)
        else:
            raise AttributeError("Passed object is not compatible with " + self.__class__.__name__ + ": " + str(java_object))
    def get_source(self):
        """
        """
        value = self.get_java_object().getSource()
        if value is None:
            return value
        else:
            return Requirement(value)
    def set_source(self, value):
        """
        """
        self.get_java_object().setSource(value.get_java_object())
    def get_target(self):
        """
        """
        value = self.get_java_object().getTarget()
        if value is None:
            return value
        else:
            return Requirement(value)
    def set_target(self, value):
        """
        """
        self.get_java_object().setTarget(value.get_java_object())