def METHOD_NAME(incoming_projections):
    """
    Gets the space needed for keys.
    :param incoming_projections:
        The projections that target the vertex in question
    :type incoming_projections:
        iterable(~spynnaker.pyNN.models.projection.Projection)
    :return: SDRAM needed
    :rtype: int
    """
    # basic sdram
    sdram = 0
    seen_app_edges = set()
    for proj in incoming_projections:
        in_edge = proj._projection_edge  # pylint: disable=protected-access
        if in_edge not in seen_app_edges:
            seen_app_edges.add(in_edge)
            sdram += BYTES_PER_WORD
            if in_edge.n_delay_stages:
                sdram += BYTES_PER_WORD
    return sdram