private String getDefinedProperty(Properties properties, String key) throws ParseException {
		String value = properties.getProperty(key);
		if (value == null || value.isEmpty()) {
			throw new ParseException("Property \"" + key + "\" is not defined.", 0);
		}
		return value;
	}
Gets the property value with the given key.

@param properties The properties to get the property from.
@param key The property's key. 
@return The property's corresponding value.
@throws ParseException if the property with the given key did not have a defined value.
GhidraBuild/LaunchSupport/src/main/java/ghidra/launch/AppConfig.java