export declare const get: {
  (key: string): (self: Headers) => Option.Option<string>
  (self: Headers, key: string): Option.Option<string>
}

export declare const has: { (key: string): (self: Headers) => boolean; (self: Headers, key: string): boolean }

export declare const merge: {
  (headers: Headers): (self: Headers) => Headers
  (self: Headers, headers: Headers): Headers
}

export declare const redact: {
  (key: string | RegExp | ReadonlyArray<string | RegExp>): (self: Headers) => Record<string, string | Redacted.Redacted>
  (self: Headers, key: string | RegExp | ReadonlyArray<string | RegExp>): Record<string, string | Redacted.Redacted>
}

export declare const remove: { (key: string): (self: Headers) => Headers; (self: Headers, key: string): Headers }

export declare const set: {
  (key: string, value: string): (self: Headers) => Headers
  (self: Headers, key: string, value: string): Headers
}

export declare const setAll: { (headers: Input): (self: Headers) => Headers; (self: Headers, headers: Input): Headers }

export declare const empty: Headers

export declare const fromInput: (input?: Input) => Headers

export declare const unsafeFromRecord: (input: Record.ReadonlyRecord<string, string>) => Headers

export declare const currentRedactedNames: FiberRef.FiberRef<readonly (string | RegExp)[]>

export interface Headers extends Redactable {
  readonly [HeadersTypeId]: HeadersTypeId
  readonly [key: string]: string
}

export type Input =
  | Record.ReadonlyRecord<string, string | ReadonlyArray<string> | undefined>
  | Iterable<readonly [string, string]>

export declare const isHeaders: (u: unknown) => u is Headers

export declare const schema: Schema.Schema<Headers, Record.ReadonlyRecord<string, string | readonly string[]>>

export declare const schemaFromSelf: Schema.Schema<Headers>

export declare const HeadersTypeId: typeof HeadersTypeId

export type HeadersTypeId = typeof HeadersTypeId