code: @Override
    public <T> long deleteObjects(Collection<T> coll) throws CpoException {
      return processUpdateGroup(coll, CpoAdapter.DELETE_GROUP, null, null, null, null);
    }
docs: Removes the Objects contained in the collection from the datasource. The assumption is that the object exists in
  the datasource. This method stores the objects contained in the collection in the datasource. The objects in the
  collection will be treated as one transaction, assuming the datasource supports transactions.
  <p/>
  This means that if one of the objects fail being deleted in the datasource then the CpoAdapter should stop
  processing the remainder of the collection, and if supported, rollback all the objects deleted thus far.
  <p/>
  <pre>Example:
  <code>
  <p/>
  class SomeObject so = null;
  class CpoAdapter cpo = null;
  <p/>
  try {
  cpo = new CpoAdapter(new JdbcDataSourceInfo(driver, url, user, password,1,1,false));
  } catch (CpoException ce) {
  // Handle the error
  cpo = null;
  }
  <p/>
  if (cpo!=null) {
  ArrayList al = new ArrayList();
  for (int i=0; i<3; i++){
  so = new SomeObject();
  so.setId(1);
  so.setName("SomeName");
  al.add(so);
  }
  try{
  cpo.deleteObjects(al);
  } catch (CpoException ce) {
  // Handle the error
  }
  }
  </code>
  </pre>
  
  @param coll This is a collection of objects that have been defined within the metadata of the datasource. If the
  class is not defined an exception will be thrown.
  @return The number of objects deleted from the datasource
  @throws CpoException Thrown if there are errors accessing the datasource