<?php
class A {
  public function printName() {
   printf('I am: "%s" called from "%s".%s', get_class($this), __CLASS__, "\n");
  }
 
  public function foo() {
    return A::printName();
  }
}
 
class B {
  public function foo() {
    A::printName();
  }
}
 
$a = new A();
$a->foo();
 
$b = new B();
$b->foo();

I am: "A" called from "A".
I am: "B" called from "A".