public String readStringEOF() {
        byte[] result = new byte[byteBuf.readableBytes()];
        byteBuf.readBytes(result);
        return new String(result, charset);
    }
@Test
    void assertReadStringEOF() {
        when(byteBuf.readableBytes()).thenReturn(0);
        assertThat(new MySQLPacketPayload(byteBuf, StandardCharsets.UTF_8).readStringEOF(), is(""));
    }