allowed masking to apply to 4D stacks
allowed masking to apply to 4D stacks


Former-commit-id: 148bab88b7dbcebf65b57b010fca423afd36e43a [formerly 1eaa5fc019eb8fee90e407ed47c4e22458bc5adf] [formerly 5b5c326ef5c7decb5a6ae87483e376af27d483e6 [formerly fd7fbeca24c44442f2d203e049e10dcd06cf8292]]
Former-commit-id: 22fe1d00a205ce4e4c8d055d5f4ea7e836666345
Former-commit-id: 7098cede8d21247a86014081da6dad6e3117364e

neurodata/ndmg