private static void readV4(DWARFLine result, BinaryReader reader, DWARFCompilationUnit cu)
			throws IOException, DWARFException {

		// length : dwarf_length (already)
		// version : 2 bytes (already)
		// header_len : dwarf_intsize
		// min_instr_len : 1 byte
		// ....
		long header_length = reader.readNextUnsignedValue(result.intSize);
		result.opcodes_start = reader.getPointerIndex() + header_length;

		result.minimum_instruction_length = reader.readNextUnsignedByte();

		if (result.dwarfVersion >= 4) {
			// Maximum operations per instruction only exists in DWARF version 4 or higher
			result.maximum_operations_per_instruction = reader.readNextUnsignedByte();
		}
		else {
			result.maximum_operations_per_instruction = 1;
		}
		result.default_is_stmt = reader.readNextUnsignedByte() != 0;
		result.line_base = reader.readNextByte();
		result.line_range = reader.readNextUnsignedByte();
		result.opcode_base = reader.readNextUnsignedByte();
		result.standard_opcode_length = new int[result.opcode_base];
		result.standard_opcode_length[0] = 1; /* Should never be used */
		for (int i = 1; i < result.opcode_base; i++) {
			result.standard_opcode_length[i] = reader.readNextUnsignedByte();
		}

		// Add the cu's compDir as element 0 of the dir table
		String defaultCompDir = cu.getCompileDirectory();
		if (defaultCompDir == null || defaultCompDir.isBlank()) {
			defaultCompDir = "";
		}
		result.directories.add(new DWARFFile(defaultCompDir));

		// Read all include directories, which are only a list of names in v4
		String dirName = reader.readNextAsciiString();
		while (dirName.length() != 0) {
			DWARFFile dir = new DWARFFile(dirName);
			dir = fixupDir(dir, defaultCompDir);

			result.directories.add(dir);
			dirName = reader.readNextAsciiString();
		}

		// Read all files, ending when null (hit empty filename)
		DWARFFile file;
		while ((file = DWARFFile.readV4(reader)) != null) {
			result.files.add(file);
		}
	}
Returns a dummy DWARFLine instance that contains no information.

@return {@link DWARFLine} instance with no info
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/dwarf/line/DWARFLine.java