flight/Engine.php
public function register($name, $class, array $params = array(), $callback = null) {
        if (method_exists($this, $name)) {
            throw new \Exception('Cannot override an existing framework method.');
        }

        $this->loader->register($name, $class, $params, $callback);
    }
public function register($name, $class, array $params = array(), $callback = null) {
        if (method_exists($this, $name)) {
            throw new \Exception('Cannot override an existing framework method.');
        }

        $this->loader->register($name, $class, $params, $callback);
    }
Registers a class to a framework method.

@param string $name Method name
@param string $class Class name
@param array $params Class initialization parameters
@param callback $callback Function to call after object instantiation
@throws \Exception If trying to map over a framework method