GraphEditor : Fix childrenViewable metadata access.
GraphEditor : Fix childrenViewable metadata access.

appleseedhq/gaffer,johnhaddon/gaffer,johnhaddon/gaffer,andrewkaufman/gaffer,boberfly/gaffer,GafferHQ/gaffer,ImageEngine/gaffer,boberfly/gaffer,andrewkaufman/gaffer,lucienfostier/gaffer,lucienfostier/gaffer,hradec/gaffer,lucienfostier/gaffer,GafferHQ/gaffer,ImageEngine/gaffer,lucienfostier/gaffer,GafferHQ/gaffer,boberfly/gaffer,andrewkaufman/gaffer,appleseedhq/gaffer,johnhaddon/gaffer,ImageEngine/gaffer,appleseedhq/gaffer,andrewkaufman/gaffer,hradec/gaffer,ivanimanishi/gaffer,johnhaddon/gaffer,ivanimanishi/gaffer,hradec/gaffer,GafferHQ/gaffer,appleseedhq/gaffer,GafferHQ/gaffer,hradec/gaffer,boberfly/gaffer,andrewkaufman/gaffer,ivanimanishi/gaffer,johnhaddon/gaffer,ivanimanishi/gaffer,hradec/gaffer,ImageEngine/gaffer