framework/di/Container.php
protected function resolveDependencies($dependencies, $reflection = null)
    {
        foreach ($dependencies as $index => $dependency) {
            if ($dependency instanceof Instance) {
                if ($dependency->id !== null) {
                    $dependencies[$index] = $this->get($dependency->id);
                } elseif ($reflection !== null) {
                    $name = $reflection->getConstructor()->getParameters()[$index]->getName();
                    $class = $reflection->getName();
                    throw new InvalidConfigException("Missing required parameter \"$name\" when instantiating \"$class\".");
                }
            }
        }

        return $dependencies;
    }
protected function resolveDependencies($dependencies, $reflection = null)
    {
        foreach ($dependencies as $index => $dependency) {
            if ($dependency instanceof Instance) {
                if ($dependency->id !== null) {
                    $dependencies[$index] = $this->get($dependency->id);
                } elseif ($reflection !== null) {
                    $name = $reflection->getConstructor()->getParameters()[$index]->getName();
                    $class = $reflection->getName();
                    throw new InvalidConfigException("Missing required parameter \"$name\" when instantiating \"$class\".");
                }
            }
        }

        return $dependencies;
    }
Resolves dependencies by replacing them with the actual object instances.
@param array $dependencies the dependencies
@param ReflectionClass $reflection the class reflection associated with the dependencies
@return array the resolved dependencies
@throws InvalidConfigException if a dependency cannot be resolved or if a dependency cannot be fulfilled.