Online PHP editor | output for OW4j1

Output for 8.3.0 - 8.3.7: Deprecated: Foo implements the Serializable interface, which is deprecated. Implement __serialize() and __unserialize() instead (or in addition, if support for old PHP versions is necessary) in /in/OW4j1 on line 3 Warning: Erroneous data format for unserializing 'Foo' in /in/OW4j1 on line 9 Warning: unserialize(): Error at offset 13 of 14 bytes in /in/OW4j1 on line 9 bool(false)
Output for 8.1.0 - 8.1.28, 8.2.0 - 8.2.18: Deprecated: Foo implements the Serializable interface, which is deprecated. Implement __serialize() and __unserialize() instead (or in addition, if support for old PHP versions is necessary) in /in/OW4j1 on line 3 Warning: Erroneous data format for unserializing 'Foo' in /in/OW4j1 on line 9 Notice: unserialize(): Error at offset 13 of 14 bytes in /in/OW4j1 on line 9 bool(false)
Output for 5.4.29, 5.5.13, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.31, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30: Warning: Erroneous data format for unserializing 'Foo' in /in/OW4j1 on line 9 Notice: unserialize(): Error at offset 13 of 14 bytes in /in/OW4j1 on line 9 bool(false)
Output for 7.3.32 - 7.3.33: Warning: Erroneous data format for unserializing 'Foo' in /in/OW4j1 on line 9 bool(false)
Output for 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.28, 5.4.30 - 5.4.45, 5.5.0 - 5.5.12, 5.5.14 - 5.5.38: object(Foo)#1 (0) { }
Output for 5.0.5: Fatal error: Interface 'Serializable' not found in /in/OW4j1 on line 3
Process exited with code 255.
Output for 5.0.0 - 5.0.4: Fatal error: Class 'Serializable' not found in /in/OW4j1 on line 3
Process exited with code 255.
Output for 4.4.2 - 4.4.9: Parse error: syntax error, unexpected T_STRING, expecting '{' in /in/OW4j1 on line 3
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.3.11, 4.4.0 - 4.4.1: Parse error: parse error, unexpected T_STRING, expecting '{' in /in/OW4j1 on line 3
Process exited with code 255.
Output for 4.3.2 - 4.3.4: Parse error: parse error, expecting `'{'' in /in/OW4j1 on line 3
Process exited with code 255.