def METHOD_NAME(filename, PetscAray):
    """Save a PETSc array to filename, in binary format
    Args:
        filename (str): path to file to save
        PetscAray (petsc4py.Mat): array to save
    """
    outputfile = os.path.join(filename)
    viewer = PETSc.Viewer().createBinary(outputfile, 'w')
    # print(help(viewer.pushFormat))
    # print(help(viewer.Format))
    # viewer.pushFormat(viewer.Format.NATIVE)
    # viewer.PetscViewerPushFormat(PETSC_VIEWER_NATIVE)
    viewer(PetscAray)