/**
 * @internal
 */
export declare enum BYTE_LENGTH_SOURCE {
    EMPTY_INPUT = "a null or undefined Body",
    CONTENT_LENGTH = "the ContentLength property of the params set by the caller",
    STRING_LENGTH = "the encoded byte length of the Body string",
    TYPED_ARRAY = "the byteLength of a typed byte array such as Uint8Array",
    LENGTH = "the value of Body.length",
    SIZE = "the value of Body.size",
    START_END_DIFF = "the numeric difference between Body.start and Body.end",
    LSTAT = "the size of the file given by Body.path on disk as reported by lstatSync"
}
/**
 * The returned value should complete the sentence, "The byte count of the data was determined by ...".
 * @internal
 * @param input - to examine.
 * @param override - manually specified value.
 * @returns source of byte count information.
 */
export declare const byteLengthSource: (input: any, override?: number) => BYTE_LENGTH_SOURCE | undefined;