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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def paths_list():
 """ Gets a folder list of possibly available QEMU binaries on the host. :returns: List of folders where Qemu binaries MAY reside. """


        paths = set()
        try:
            paths.add(os.getcwd())
        except FileNotFoundError:
            log.warning("The current working directory doesn't exist")
        if "PATH" in os.environ:
            paths.update(os.environ["PATH"].split(os.pathsep))
        else:
            log.warning("The PATH environment variable doesn't exist")
        # look for Qemu binaries in the current working directory and $PATH
        if sys.platform.startswith("win"):
            # add specific Windows paths
            if hasattr(sys, "frozen"):
                # add any qemu dir in the same location as gns3server.exe to the list of paths
                exec_dir = os.path.dirname(os.path.abspath(sys.executable))
                for f in os.listdir(exec_dir):
                    if f.lower().startswith("qemu"):
                        paths.add(os.path.join(exec_dir, f))

            if "PROGRAMFILES(X86)" in os.environ and os.path.exists(os.environ["PROGRAMFILES(X86)"]):
                paths.add(os.path.join(os.environ["PROGRAMFILES(X86)"], "qemu"))
            if "PROGRAMFILES" in os.environ and os.path.exists(os.environ["PROGRAMFILES"]):
                paths.add(os.path.join(os.environ["PROGRAMFILES"], "qemu"))
        elif sys.platform.startswith("darwin"):
            if hasattr(sys, "frozen"):
                # add specific locations on Mac OS X regardless of what's in $PATH
                paths.update(["/usr/bin", "/usr/local/bin", "/opt/local/bin"])
                try:
                    exec_dir = os.path.dirname(os.path.abspath(sys.executable))
                    paths.add(os.path.abspath(os.path.join(exec_dir, "../Resources/qemu/bin/")))
                # If the user run the server by hand from outside
                except FileNotFoundError:
                    paths.add("/Applications/GNS3.app/Contents/Resources/qemu/bin")
        return paths