private Address getFileAddress(Program program, String addressString) {
		if (fromAddress == null) {
			return null;
		}
		try {
			Address address = fromAddress.getAddressSpace().getAddress(addressString);
			if (address != null && program.getMemory().contains(address)) {
				return address;
			}
		}
		catch (AddressFormatException e) {
			// ignore and return null
		}
		return null;
	}
Regex used for going to a file offset.  We expect something of the form <code>file(n)</code>,
where <code>n</code> can be hex or decimal.  Spaces should be ignored.
Ghidra/Features/Base/src/main/java/ghidra/app/util/navigation/GoToQuery.java