tests/PsrCache/PoolTest.php
/**
     * It MUST NOT be considered an error condition if the specified key does
     * not exist. The post-condition is the same (the key does not exist, or
     * the pool is empty), thus there is no error condition.
     */
It MUST NOT be considered an error condition if the specified key does
not exist. The post-condition is the same (the key does not exist, or
the pool is empty), thus there is no error condition.
It MUST NOT be considered an error condition if the specified key does not exist . The post - condition is the same ( the key does not exist or the pool is empty ) thus there is no error condition .
public function testDeleteNonExistant()
    {
        $this->assertTrue($this->pool->deleteItem('non-existant'));
        $this->assertFalse($this->pool->hasItem('non-existant'));
    }
public function testDeleteNonExistant ( ) { $ this -> assertTrue ( $ this -> pool -> deleteItem ( 'non-existant' ) ) ; $ this -> assertFalse ( $ this -> pool -> hasItem ( 'non-existant' ) ) ; }
It MUST NOT be considered an error condition if the specified key does
 not exist.
It MUST NOT be considered an error condition if the specified key does not exist .