src/Composer/Installer/InstallationManager.php
public function ensureBinariesPresence(PackageInterface $package)
    {
        try {
            $installer = $this->getInstaller($package->getType());
        } catch (\InvalidArgumentException $e) {
            // no installer found for the current package type (@see `getInstaller()`)
            return;
        }

        // if the given installer support installing binaries
        if ($installer instanceof BinaryPresenceInterface) {
            $installer->ensureBinariesPresence($package);
        }
    }
public function ensureBinariesPresence(PackageInterface $package)
    {
        try {
            $installer = $this->getInstaller($package->getType());
        } catch (\InvalidArgumentException $e) {
            // no installer found for the current package type (@see `getInstaller()`)
            return;
        }

        // if the given installer support installing binaries
        if ($installer instanceof BinaryPresenceInterface) {
            $installer->ensureBinariesPresence($package);
        }
    }
Install binary for the given package.
If the installer associated to this package doesn't handle that function, it'll do nothing.

@param PackageInterface $package Package instance