Checks for the given binary in the places, defined by the environment
    variables SUMO_HOME and <NAME>_BINARY.

def checkBinary(name, bindir=None):
    """
    Checks for the given binary in the places, defined by the environment
    variables SUMO_HOME and <NAME>_BINARY.
    """
    if name == "sumo-gui":
        envName = "GUISIM_BINARY"
    else:
        envName = name.upper() + "_BINARY"
    env = os.environ
    join = os.path.join
    if envName in env and exeExists(env.get(envName)):
        return env.get(envName)
    if bindir is not None:
        binary = join(bindir, name)
        if exeExists(binary):
            return binary
    if "SUMO_HOME" in env:
        binary = join(env.get("SUMO_HOME"), "bin", name)
        if exeExists(binary):
            return binary
    binary = os.path.abspath(
        join(os.path.dirname(__file__), '..', '..', 'bin', name))
    if exeExists(binary):
        return binary
    return name