code: private DescribeVpcsResponseType describeVpcs() {
          DescribeVpcsResponseType ret = new DescribeVpcsResponseType();
          ret.setRequestId(UUID.randomUUID().toString());
          VpcSetType vpcSet = new VpcSetType();
          for (Iterator<MockVpc> mockVpc = mockVpcController.describeVpcs().iterator(); mockVpc
                  .hasNext();) {
              MockVpc item = mockVpc.next();
  
              VpcType vpcType = new VpcType();
              if (!DEFAULT_MOCK_PLACEMENT.getAvailabilityZone().equals(currentRegion)) {
                  vpcType.setVpcId(currentRegion + "_" + item.getVpcId());
              } else {
                  vpcType.setVpcId(item.getVpcId());
              }
  
              vpcType.setState(item.getState());
              vpcType.setCidrBlock(item.getCidrBlock());
              vpcType.setIsDefault(item.getIsDefault());
  
              vpcSet.getItem().add(vpcType);
          }
          ret.setVpcSet(vpcSet);
  
          return ret;
      }
docs: Handles "describeVpcs" request and returns response with a vpc.
  
  @return a DescribeVpcsResponseType with our predefined vpc in aws-mock.properties (or if not overridden, as
  defined in aws-mock-default.properties)