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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 get_imported_modules(cells, nb_module_name=''):
    "Finds all submodules of notebook - sorted by submodules > top level modules > manual imports. This gives notebook imports priority"
    module_names = get_top_level_modules()
    nb_imports = [match.group(1) for cell in cells for match in IMPORT_RE.finditer(cell['source']) if cell['cell_type'] == 'code']
    parts = nb_module_name.split('.')
    parent_modules = ['.'.join(parts[:(x+1)]) for x in range_of(parts)] # Imports parent modules - a.b.c = [a, a.b, a.b.c]
    all_modules = module_names + nb_imports + parent_modules
    mods = [import_mod(m, ignore_errors=True) for m in all_modules]
    return [m for m in mods if m is not None]