def METHOD_NAME(dtype):
    """Map numpy types to MPI datatypes."""
    # Resolve vector dtype if necessary
    dtype = dtypes_vector_mapper.get_base_dtype(dtype)
    return {
        np.ubyte: 'MPI_BYTE',
        np.ushort: 'MPI_UNSIGNED_SHORT',
        np.int32: 'MPI_INT',
        np.float32: 'MPI_FLOAT',
        np.int64: 'MPI_LONG',
        np.float64: 'MPI_DOUBLE'
    }[dtype]