text: /*
   * Copyright 2020 ConsenSys AG.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
   * the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
   * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
   * specific language governing permissions and limitations under the License.
   */
  
  package tech.pegasys.teku.statetransition.attestation;
  
  import java.util.ArrayList;
  import java.util.List;
  import tech.pegasys.teku.bls.BLS;
  import tech.pegasys.teku.bls.BLSSignature;
  import tech.pegasys.teku.datastructures.operations.Attestation;
  import tech.pegasys.teku.ssz.SSZTypes.Bitlist;
  
  public class AggregatorUtil {
    public static Attestation aggregateAttestations(
        final Attestation firstAttestation, final Attestation... attestations) {
      final Bitlist aggregateBits = firstAttestation.getAggregation_bits().copy();
      final List<BLSSignature> signatures = new ArrayList<>();
      signatures.add(firstAttestation.getAggregate_signature());
  
      for (Attestation attestation : attestations) {
        aggregateBits.setAllBits(attestation.getAggregation_bits());
        signatures.add(attestation.getAggregate_signature());
      }
      return new Attestation(aggregateBits, firstAttestation.getData(), BLS.aggregate(signatures));
    }
  }
  