注意: このページはまだ日本語に翻訳されていません。以下は英語の原文です。 
type ProviderEvent: 
  | string
  | (string | string[])[]
  | EventFilter
  | OrphanFilter
  | AccessesFilter;
A ProviderEvent provides the types of events that can be subscribed to on a Provider. Each provider may include additional possible events it supports, but the most commonly supported are: "block" - calls the listener with the current block number on each new block. "error" - calls the listener on each async error that occurs during the event loop, with the error. "debug" - calls the listener on debug events, which can be used to troubleshoot network errors, provider problems, etc. transaction hash - calls the listener on each block after the transaction has been mined; generally .once is more appropriate for this event. Array - calls the listener on each log that matches the filter. EventFilter - calls the listener with each matching log

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Source

providers/provider.ts:2709