### Question:
IoTDBConnection implements Connection { public void setTimeZone(String zoneId) throws TException, IoTDBSQLException { TSSetTimeZoneReq req = new TSSetTimeZoneReq(zoneId); TSSetTimeZoneResp resp = client.setTimeZone(req); Utils.verifySuccess(resp.getStatus()); this.zoneId = ZoneId.of(zoneId); } IoTDBConnection();  IoTDBConnection(String url, Properties info); static TSIService.Iface newSynchronizedClient(TSIService.Iface client); @Override boolean isWrapperFor(Class<?> arg0); @Override T unwrap(Class<T> arg0); @Override void abort(Executor arg0); @Override void clearWarnings(); @Override void close(); @Override void commit(); @Override Array createArrayOf(String arg0, Object[] arg1); @Override Blob createBlob(); @Override Clob createClob(); @Override NClob createNClob(); @Override SQLXML createSQLXML(); @Override Statement createStatement(); @Override Statement createStatement(int resultSetType, int resultSetConcurrency); @Override Statement createStatement(int arg0, int arg1, int arg2); @Override Struct createStruct(String arg0, Object[] arg1); @Override boolean getAutoCommit(); @Override void setAutoCommit(boolean arg0); @Override String getCatalog(); @Override void setCatalog(String arg0); @Override Properties getClientInfo(); @Override void setClientInfo(Properties arg0); @Override String getClientInfo(String arg0); @Override int getHoldability(); @Override void setHoldability(int arg0); @Override DatabaseMetaData getMetaData(); @Override int getNetworkTimeout(); @Override String getSchema(); @Override void setSchema(String arg0); @Override int getTransactionIsolation(); @Override void setTransactionIsolation(int arg0); @Override Map<String, Class<?>> getTypeMap(); @Override void setTypeMap(Map<String, Class<?>> arg0); @Override SQLWarning getWarnings(); @Override boolean isClosed(); @Override boolean isReadOnly(); @Override void setReadOnly(boolean arg0); @Override boolean isValid(int arg0); @Override String nativeSQL(String arg0); @Override CallableStatement prepareCall(String arg0); @Override CallableStatement prepareCall(String arg0, int arg1, int arg2); @Override CallableStatement prepareCall(String arg0, int arg1, int arg2, int arg3); @Override PreparedStatement prepareStatement(String sql); @Override PreparedStatement prepareStatement(String sql, int autoGeneratedKeys); @Override PreparedStatement prepareStatement(String sql, int[] columnIndexes); @Override PreparedStatement prepareStatement(String sql, String[] columnNames); @Override PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency); @Override PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency,
      int resultSetHoldability); @Override void releaseSavepoint(Savepoint arg0); @Override void rollback(); @Override void rollback(Savepoint arg0); @Override void setClientInfo(String arg0, String arg1); @Override void setNetworkTimeout(Executor arg0, int arg1); @Override Savepoint setSavepoint(); @Override Savepoint setSavepoint(String arg0); boolean reconnect(); String getTimeZone(); void setTimeZone(String zoneId); ServerProperties getServerProperties(); TSProtocolVersion getProtocol(); void setProtocol(TSProtocolVersion protocol); public TSIService.Iface client; public TS_SessionHandle sessionHandle; }### Answer:
@Test public void testSetTimeZone() throws TException, IoTDBSQLException { String timeZone = "Asia/Shanghai"; when(client.setTimeZone(any(TSSetTimeZoneReq.class))) .thenReturn(new TSSetTimeZoneResp(Status_SUCCESS)); connection.client = client; connection.setTimeZone(timeZone); assertEquals(connection.getTimeZone(), timeZone); }