def maybe_merge_mappings(mapping_1, mapping_2):
    """
    Merges the two maybe mapping if applicable returning a new one.
    
    Parameters
    ----------
    mapping_1 : `None`, `mapping`
        Mapping to merge.
    mapping_2 : `None`, `mapping`
        Mapping to merge.
    
    Returns
    -------
    merged : `None`, `dict`
    """
    if (mapping_1 is not None) and (not mapping_1):
        mapping_1 = None
    
    if (mapping_2 is not None) and (not mapping_2):
        mapping_2 = None
    
    if mapping_1 is None:
        if mapping_2 is None:
            merged = None
        else:
            merged = {**mapping_2}
    else:
        if mapping_2 is None:
            merged = {**mapping_1}
        else:
            merged = {**mapping_1, **mapping_2}
    
    return merged