Description:
------------
I think the non-static method of class should be have independence in different object of this class.
For example,The static variable what is in the non-static method of class should not be shared in different object. 


Test script:
---------------
class Test
{
    public function print_index()
    {
         static $index=0;//the static*
         return $index++;
    }
}
$obj1=new Test;
$obj2=new Test;
                                         //I think there should be
echo $obj1->print_index().PHP_EOL;//result:0      0
echo $obj2->print_index().PHP_EOL;//result:1      0
echo $obj1->print_index().PHP_EOL;//result:2      1
echo $obj2->print_index().PHP_EOL;//result:3      1

Expected result:
----------------
0
0
1
1

Actual result:
--------------
0
1
2
3