private int depth(String line) {
		int i = 0;
		while (i < line.length() && line.charAt(i) == ' ') {
			i++;
		}
		return i / 2;
	}
Gets the tree-depth of this {@link SwiftNode}

@param line A line of output from <code>swift demangle --tree-only</code>
@return The tree-depth of this {@link SwiftNode}
Ghidra/Features/SwiftDemangler/src/main/java/ghidra/app/util/demangler/swift/SwiftDemangledTree.java