(*pageBits)(b).setRange(i, n)
}

// allocAll allocates all the bits of b.
func (b *pallocBits) allocAll() {
	(*pageBits)(b).setAll()
}

// free1 frees a single page in the pallocBits at i.
func (b *pallocBits) free1(i uint) {
	(*pageBits)(b).clear(i)
}

// free frees the range [i, i+n) of pages in the pallocBits.
func (b *pallocBits) free(i, n uint) {
	(*pageBits)(b).clearRange(i, n)
}

	if npages == 1 {
		// Fast path: we're clearing a single bit, and we know exactly
		// where it is, so mark it directly.
		i := chunkIndex(base)
		pi := chunkPageIndex(base)
		p.chunkOf(i).free1(pi)
		p.scav.index.free(i, pi, 1)
	} else {
		// Slow path: we're clearing more bits so we may need to iterate.
		sc, ec := chunkIndex(base), chunkIndex(limit)
		si, ei := chunkPageIndex(base), chunkPageIndex(limit)

        FileVisitDetails fileVisitDetails1 = fileVisitDetails(file1)
        FileVisitDetails fileVisitDetails2 = fileVisitDetails(file2)
        def tree1 = new TestFileTree([fileVisitDetails1])
        def tree2 = new TestFileTree([fileVisitDetails2])

        when:
        FileTree sum = tree1.plus(tree2)

        then:
        sum.files.sort() == [file1, file2]
    }

    def "can add file trees together using + operator"() {

    def "dependencies are union of dependencies of source trees"() {
        def task1 = Stub(Task)
        def task2 = Stub(Task)
        def task3 = Stub(Task)
        def tree1 = Stub(FileTreeInternal)
        def tree2 = Stub(FileTreeInternal)

        given:
        tree1.visitDependencies(_) >> { TaskDependencyResolveContext context ->
            context.add(task1)
            context.add(task2)
        }

        def file2 = dir1.createFile("file2")
        def dir2 = baseDir.createDir("dir2")
        def file3 = dir2.createFile("other/file3")

        expect:
        def tree1 = baseDirectory.asFileTree
        tree1.files == [file1, file2, file3] as Set

        and:
        def tree2 = baseDirectory.dir("dir2").get().asFileTree
        tree2.files == [file3] as Set
    }