code: func (c *signerInfoContext) Keys() string {
  	sort.Strings(c.s.Keys)
  	truncatedKeys := []string{}
  	if c.trunc {
  		for _, keyID := range c.s.Keys {
  			truncatedKeys = append(truncatedKeys, stringid.TruncateID(keyID))
  		}
  		return strings.Join(truncatedKeys, ", ")
  	}
  	return strings.Join(c.s.Keys, ", ")
  }
docs: // Keys returns the sorted list of keys associated with the signer