    def __new__(cls, sourceName: str):
        """Dispatches to the right subclass."""
        if cls != InputSource:
            # Only take control of calls to InputSource(...) itself.
            return super().__new__(cls)

        if sourceName == "-":
            return StdinInputSource(sourceName)
        if sourceName.startswith("https:"):
            return UrlInputSource(sourceName)
        return FileInputSource(sourceName)
The software constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.