Signature Metadata
SignatureMeta is required to add extra meta-data to a transaction's signature. It currently supports platformVersion only, but it can be extended to support a universal digital signature model enabling partial signatures and attaching extra information, such as a user's timestamp or other application-specific fields.
Parameters
platform Version
current DLT version.
scheme Number ID
number id of the signature scheme used based on signer's key-pair, see SignatureScheme.schemeNumberID.