} else {
		return "", false, nil
	}

	// Check that there aren't other modules in the way.
	// This check is unnecessary inside the module cache
	// and important to skip in the vendor directory,
	// where all the module trees have been overlaid.
	// So we only check local module trees
	// (the main module, and any directory trees pointed at by replace directives).
	if isLocal {

// In this example, "rsc.io/qr" is both a module path and an import path.
// But "rsc.io/qr/gf256" is only an import path, not a module path:
// it names an importable package, but not a module.
//
// As a special case to incorporate code written before modules were
// introduced, if a path p resolves using the pre-module "go get" lookup
// to the root of a source code repository without a go.mod file,

[[sub::terminology_platform]]
== Platform

A platform is a set of modules aimed to be used together. There are different categories of platforms, corresponding to different use cases:

- module set: often a set of modules published together as a whole. Using one module of the set often means we want to use the same version for all modules of the set. For example, if using `groovy` 1.2, also use `groovy-json` 1.2.

    @Override
    IvyModule dependencyConstraint(Module target) {
        dependencyConstraints << [organisation: target.group, module: target.module, revision: target.version]
        return this
    }

    @Override
    IvyModule dependencyConstraint(Map<String, ?> attributes, Module module) {
        def allAttrs = [organisation: module.group, module: module.module, revision: module.version]
        allAttrs.putAll(attributes)

    def expectGetDynamicRevision(IvyHttpModule module) {
        expectListVersions(module)
        module.ivy.expectGet()
        module.jar.expectGet()
    }

    def expectGetDynamicRevisionMetadata(IvyHttpModule module) {
        expectListVersions(module)
        module.ivy.expectGet()
    }

    private expectListVersions(IvyHttpModule module) {

  into 'libs'
}
"""
        ivyRepo.module('org', 'projectA', '1.2')
            .dependsOn(organisation: 'org', module: 'projectB', revision: '1.5', revConstraint: '1.6')
            .dependsOn(organisation: 'org', module: 'projectC', revision: 'alpha-12')
            .publish()

        ivyRepo.module('org', 'projectB', '1.5')
            .publish()

        ivyRepo.module('org', 'projectB', '1.6')
            .publish()

	sha256SchemePrefix = "sha256:"
)

// Cache models a Wasm module cache.
type Cache interface {
	Get(url string, opts GetOptions) (string, error)
	Cleanup()
}

// LocalFileCache for downloaded Wasm modules. Currently it stores the Wasm module as local file.
type LocalFileCache struct {
	// Map from Wasm module checksum to cache entry.
	modules map[moduleKey]*cacheEntry
	// Map from tagged URL to checksum

        def moduleA = sysPropRepo.module('group', 'projectA', '1.2').publish()

        when:
        run 'retrieve'

        then:
        hasArtifact(moduleA)
    }

    def "can resolve artifacts from local m2 with custom local repository defined by system-property"() {
        given:
        def artifactRepo = mavenLocal("artifactrepo")
        def moduleA = artifactRepo.module('group', 'projectA', '1.2').publish()

                }
            }
        """
        when:
        succeeds 'publish'

        then:
        def module = ivyRepo.module('org.gradle.test', 'root', '1.0')
        module.assertPublished()
        def module2 = ivyRepo2.module('org.gradle.test', 'root', '1.0')
        module2.assertPublished()
    }

    def "can publish custom PublishArtifact"() {
        given:

	"cmd/go/internal/modload"
	"cmd/go/internal/toolchain"

	"golang.org/x/mod/module"
)

var cmdDownload = &base.Command{
	UsageLine: "go mod download [-x] [-json] [-reuse=old.json] [modules]",
	Short:     "download modules to local cache",
	Long: `
Download downloads the named modules, which can be module patterns selecting
dependencies of the main module or module queries of the form path@version.