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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_user_tables(conn):
 """Retrieve all user tables."""


    query_string = "select schemaname, relname from pg_stat_user_tables;"
    with conn.cursor() as cursor:
        cursor.execute(query_string)
        tables = cursor.fetchall()

    return tables