This returns a Promise which resolves to the [Raw Signature](/v5/api/utils/bytes/#signature-raw) of *message*.
Sub-classes **must** implement this, however they may throw if signing a message is not supported, such as in a Contract-based Wallet or Meta-Transaction-based Wallet.
#### Note
If *message* is a string, it is **treated as a string** and converted to its representation in UTF8 bytes.
**If and only if** a message is a [Bytes](/v5/api/utils/bytes/#Bytes) will it be treated as binary data.
For example, the string `"0x1234"` is 6 characters long (and in this case 6 bytes long). This is **not** equivalent to the array `[ 0x12, 0x34 ]`, which is 2 bytes long.
A common case is to sign a hash. In this case, if the hash is a string, it **must** be converted to an array first, using the [arrayify](/v5/api/utils/bytes/#utils-arrayify) utility function.
Returns a Promise which resolves to the signed transaction of the *transactionRequest*. This method does not populate any missing fields.
Sub-classes **must** implement this, however they may throw if signing a transaction is not supported, which is common for security reasons in many clients.
This method populates the transactionRequest with missing fields, using [populateTransaction](/v5/api/signer/#Signer-populateTransaction) and returns a Promise which resolves to the transaction.
Sub-classes **must** implement this, however they may throw if sending a transaction is not supported, such as the [VoidSigner](/v5/api/signer/#VoidSigner) or if the Wallet is offline and not connected to a [Provider](/v5/api/providers/provider/).
Signs the typed data *value* with *types* data structure for *domain* using the [EIP-712](https://eips.ethereum.org/EIPS/eip-712) specification.
#### Experimental feature (this method name will change)
This is still an experimental feature. If using it, please specify the **exact** version of ethers you are using (e.g. spcify `"5.0.18"`, **not**`"^5.0.18"`) as the method name will be renamed from `_signTypedData` to `signTypedData` once it has been used in the field a bit.
This should return a **copy** of the *transactionRequest*, with any properties needed by `call`, `estimateGas` and `populateTransaction` (which is used by sendTransaction). It should also throw an error if any unknown key is specified.
The default implementation checks only if valid [TransactionRequest](/v5/api/providers/types/#providers-TransactionRequest) properties exist and adds `from` to the transaction if it does not exist.
This should return a **copy** of *transactionRequest*, follow the same procedure as `checkTransaction` and fill in any properties required for sending a transaction. The result should have all promises resolved; if needed the [resolveProperties](/v5/api/utils/properties/#utils-resolveproperties) utility function can be used for this.
The default implementation calls `checkTransaction` and resolves to if it is an ENS name, adds `gasPrice`, `nonce`, `gasLimit` and `chainId` based on the related operations on Signer.
Returns a new Wallet with a random private key, generated from cryptographically secure entropy sources. If the current environment does not have a secure entropy source, an error is thrown.
Wallets created using this method will have a mnemonic.
This operation will operate synchronously which will lock up the user interface, possibly for a non-trivial duration. Most applications should use the asynchronous `fromEncryptedJson` instead.
The provider this wallet is connected to, which will be used for any [Blockchain Methods](/v5/api/signer/#Signer--blockchain-methods) methods. This can be null.
A **Wallet** instance is immutable, so if you wish to change the Provider, you may use the [connect](/v5/api/signer/#Signer-connect) method to create a new instance connected to the desired provider.
