code: def checkBinary(name, bindir=None):
      
      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
docs: Checks for the given binary in the places, defined by the environment
      variables SUMO_HOME and <NAME>_BINARY.