src/Composer/Installer/InstallationManager.php
public function removeInstaller(InstallerInterface $installer)
    {
        if (false !== ($key = array_search($installer, $this->installers, true))) {
            array_splice($this->installers, $key, 1);
            $this->cache = array();
        }
    }
public function removeInstaller(InstallerInterface $installer)
    {
        if (false !== ($key = array_search($installer, $this->installers, true))) {
            array_splice($this->installers, $key, 1);
            $this->cache = array();
        }
    }
Removes installer

@param InstallerInterface $installer installer instance