input: Write a python function to parse command-line arguments and return them in a dictionary.
  assert parse_args(["--clusters", "svc1,svc2", "--user", "admin", "--password", "pwd", "--discovery-types", "volume-mdisk"]) == {"clusters": ["svc1", "svc2"], "user": "admin", "password": "pwd", "discovery-types": ["volume-mdisk"]}
  assert parse_args(["--clusters", "svc1", "--user", "admin", "--password", "pwd", "--discovery-types", "volume"]) == {"clusters": ["svc1"], "user": "admin", "password": "pwd", "discovery-types": ["volume"]}
  assert parse_args(["--clusters", "svc1,svc2", "--user", "admin", "--password", "pwd"]) == {"clusters": ["svc1", "svc2"], "user": "admin", "password": "pwd", "discovery-types": []}
output: def parse_args(args):
      result = {}
      i = 0
      while i < len(args):
          if args[i].startswith("--"):
              key = args[i][2:]
              if key in ["clusters", "discovery-types"]:
                  result[key] = args[i + 1].split(",")
              else:
                  result[key] = args[i + 1]
              i += 2
          else:
              i += 1
      if "discovery-types" not in result:
          result["discovery-types"] = []
      return result