CustomBindingExtension.java

import com.icfolson.aem.groovy.console.api.BindingExtensionProvider;
import com.icfolson.aem.groovy.console.api.BindingVariable;
import com.icfolson.aem.groovy.console.api.context.ScriptContext;
import org.osgi.service.component.annotations.Component;

import java.util.HashMap;
import java.util.Map;

// Tells the Groovy Console bundle to use this class as an extension to the default Binding
@Component(service = BindingExtensionProvider.class, immediate = true)

// Implementing this class gives us the method signature below
public class CustomBindingExtension implements BindingExtensionProvider {

    @Override
    public Map<String, BindingVariable> getBindingVariables(final ScriptContext scriptContext) {

        // Simply return a map representing each new binding variable you wish to add, in this case just one
        final HashMap<String, BindingVariable> bindingVariables = new HashMap<>();
        bindingVariables.put("importer", new BindingVariable(new Importer()));
        return bindingVariables;
    }
}