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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def map_indices_parent2child(child, parent_indices):
 """Map parent RTDCBase event indices to RTDC_Hierarchy Parameters parent: RTDC_Hierarchy hierarchy child parent_indices: 1d ndarray hierarchy parent (`child.hparent`) indices to map Returns ------- child_indices: 1d ndarray child indices """

    parent = child.hparent
    # filters
    pf = parent.filter.all
    # indices in child
    child_indices = []
    count = 0
    for ii in range(len(pf)):
        if pf[ii]:
            # only append indices if they exist in child
            if ii in parent_indices:
                # current child event count is the child index
                child_indices.append(count)
            # increment child event count
            count += 1

    return np.array(child_indices)