code: public final String getChainIdentity(String separator) throws KSIException {
          StringBuilder identity = new StringBuilder();
  
          for (int i = chain.size()-1; i >=0 ; i--) {
              AggregationChainLink aggregationChainLink = chain.get(i);
              Identity linkIdentity = aggregationChainLink.getLinkIdentity();
              String id = linkIdentity == null ? "" : linkIdentity.getDecodedClientId();
              if (identity.length() > 0 && id.length() > 0) {
                  identity.append(separator);
              }
              identity.append(id);
          }
          return identity.toString();
      }
docs: Returns the (partial) signer identity from the current hash chain.