implementation-class=org.gradle.testfixtures.CustomPlugin...

implementation-class=org.gradle.api.internal.plugins.CustomPlugin...

                String getValue() {
                    return "myValue";
                }
            }

            class CustomPlugin implements Plugin<Project> {
                @Inject
                CustomPlugin(ToolingModelBuilderRegistry registry) {
                    registry.register(new CustomBuilder());
                    registry.register(new CustomBuilder2());
                }

        return modelName == '${CustomModel.name}'
    }
    Object buildAll(String modelName, Project project) {
        return new CustomModel(50)
    }
}

class CustomPlugin implements Plugin<Project> {
    @Inject
    CustomPlugin(ToolingModelBuilderRegistry registry) {
        registry.register(new CustomBuilder())
    }

    public void apply(Project project) {
    }
}
"""
        withBuildScriptIn("a")

			if customPlugin, ok := enabledCustomPlugins[defaultEnabledPlugin.Name]; ok {
				logger.Info("Default plugin is explicitly re-configured; overriding", "plugin", defaultEnabledPlugin.Name)
				// Update the default plugin in place to preserve order.
				defaultEnabledPlugin = customPlugin.plugin
				replacedPluginIndex.Insert(customPlugin.index)
			}

        project.gradle.gradleUserHomeDir == project.file('userHome')
    }

    def canApplyACustomPluginUsingClass() {
        when:
        def project = buildProject()
        project.apply plugin: CustomPlugin

        then:
        project.tasks.hello instanceof DefaultTask
    }

    def canApplyACustomPluginById() {
        when:
        def project = buildProject()