src/Zend/Cache/Core.php
public function setOption($name, $value)
    {
        if (!is_string($name)) {
            Zend_Cache::throwException("Incorrect option name!");
        }
        $name = strtolower($name);
        if (array_key_exists($name, $this->_options)) {
            // This is a Core option
            $this->_setOption($name, $value);
            return;
        }
        if (array_key_exists($name, $this->_specificOptions)) {
            // This a specic option of this frontend
            $this->_specificOptions[$name] = $value;
            return;
        }
    }
public function setOption($name, $value)
    {
        if (!is_string($name)) {
            Zend_Cache::throwException("Incorrect option name!");
        }
        $name = strtolower($name);
        if (array_key_exists($name, $this->_options)) {
            // This is a Core option
            $this->_setOption($name, $value);
            return;
        }
        if (array_key_exists($name, $this->_specificOptions)) {
            // This a specic option of this frontend
            $this->_specificOptions[$name] = $value;
            return;
        }
    }
Public frontend to set an option

There is an additional validation (relatively to the protected _setOption method)

@param  string $name  Name of the option
@param  mixed  $value Value of the option
@throws Zend_Cache_Exception
@return void