isTxMetadataAttrString
export function isTxMetadataAttrString(attr: PermissiveTxMetadataAttr): attr is stringArguments
1. attr
attr: PermissiveTxMetadataAttrReturns
attr is string
export function isTxMetadataAttrString(attr: PermissiveTxMetadataAttr): attr is stringattrattr: PermissiveTxMetadataAttrattr is string