This issue is supposed to track when we can start to use explicit type aliases (PEP 613) in typeshed. Support is needed in released versions of:

• mypy (Support PEP 613 mypy#9404)
  • Explicit type aliases fail in typeshed mypy#12422
• pytype (Support PEP 613: Explicit Type Aliases google/pytype#787)
  • Problems with explicit type aliases in typeshed google/pytype#1159
• pyright (Implement PEP 613 microsoft/pyright#655)
• pyre
• PyCharm PY-42334