Multiple inheritance isn't allowed in PHP. [It's not] possible with PHP (in Java is not possible either), but today we can do something similar (is not the exactly the same) with Traits. Let me explain that: Instead of classes we can create Traits.
He includes a code example showing the creation of two traits, "Base1" and "Base2", that are implemented (via "use") and the calls to methods on each. He also points out the error condition and message that can come up when there's a conflict in the method names between two or more traits. This is relatively easy to solve with the mapping ability of the "use" statement (code example included for that too).