static fun forSignatureKeyPair(keyPair: KeyPair!): KeyPair! (source)
Converts signature key pair (Ed25519) to a box key pair (Curve25519) so that the same key pair can be used both for authenticated encryption and for signatures. See https://libsodium.gitbook.io/doc/advanced/ed25519-curve25519
keyPair - KeyPair!: A Signature.KeyPair.
Return
KeyPair!: A KeyPair.