code: public java.util.List<EC2SecurityGroup> getEC2SecurityGroups() {
          if (eC2SecurityGroups == null) {
              eC2SecurityGroups = new com.amazonaws.internal.SdkInternalList<EC2SecurityGroup>();
          }
          return eC2SecurityGroups;
      }
docs: <p>
  A list of EC2 security groups that are permitted to access clusters associated with this cluster security group.
  </p>
  
  @return A list of EC2 security groups that are permitted to access clusters associated with this cluster security
  group.