In other words, you can use a file tree wherever a file collection is required, but remember that a file collection is a flat list/set of files, while a file tree is a file and directory hierarchy.
To convert a file tree to a flat collection, use the link:{javadocPath}/org/gradle/api/file/FileTree.html#getFiles--[FileTree.getFiles()] property.

    color:var(--block-text-color);
}
.deprecated-label, .description-from-type-label, .implementation-label, .member-name-link,
.module-label-in-package, .module-label-in-type, .package-label-in-type,
.package-hierarchy-label, .type-name-label, .type-name-link, .search-tag-link, .preview-label {
    font-weight:bold;
}
.deprecation-comment, .help-footnote, .preview-comment {
    font-style:italic;
}
.deprecation-block {

        // and there is a nested class A$X. we want to be able
        // to access that class directly, so A becomes a valid
        // name in X.
        // GROOVY-4043: Do this check up the hierarchy, if needed
        Map<String, ClassNode> classHierarchy = new LinkedHashMap<String, ClassNode>();
        ClassNode val;
        for (ClassNode classToCheck = currentClass;
            /*

		expectedBuf []byte
		expectedErr error
	}{
		// Successful read at offset 0 and proper buffer size. - 1
		{
			volume, "myobject", 0, 5,
			[]byte("hello"), nil,
		},
		// Success read at hierarchy. - 2
		{
			volume, "path/to/my/object", 0, 5,
			[]byte("hello"), nil,
		},
		// Object is a directory. - 3
		{
			volume, "object-as-dir",
			0, 5, nil, errIsNotRegular,
		},

                      << gtest_error

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// Use ImplicitCast_ as a safe version of static_cast for upcasting in
// the type hierarchy (e.g. casting a Foo* to a SuperclassOfFoo* or a
// const Foo*).  When you use ImplicitCast_, the compiler checks that
// the cast is safe.  Such explicit ImplicitCast_s are necessary in

                      << gtest_error

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// Use ImplicitCast_ as a safe version of static_cast for upcasting in
// the type hierarchy (e.g. casting a Foo* to a SuperclassOfFoo* or a
// const Foo*).  When you use ImplicitCast_, the compiler checks that
// the cast is safe.  Such explicit ImplicitCast_s are necessary in