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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_LDAP_connection():
 """ Return a LDAP connection """

    server = ldap3.Server('ldap://' + get_optional_env('EPFL_LDAP_SERVER_FOR_SEARCH'))
    connection = ldap3.Connection(server)
    connection.open()

    return connection, get_optional_env('EPFL_LDAP_BASE_DN_FOR_SEARCH')