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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 check_in(request, action):
 """This function checks for missing properties in the request dict for the corresponding action."""

    if not request:
        req_str = ""
        for idx, val in enumerate(actions[action]):
            req_str += "\n" + val
        erstr = "Provide a request dict with the following properties:" \
                " %s" % req_str
        raise ValueError(erstr)

    required_fields = actions[action]
    missing = []
    for field in required_fields:
        if not is_key_present(request, field):
            missing.append(field)
    if missing:
        missing_string = ""
        for idx, val in enumerate(missing):
            missing_string += "\n" + val
        erstr = "Provide the required request parameters to" \
                " complete this request: %s" % missing_string
        raise ValueError(erstr)

    return True