code: public void sequenceGenerator(String name, String sequenceName, Integer initialValue, Integer allocationSize) {
  		checkReadOnly();
  		this.addGenerator(new SequenceIdGenerator(name, sequenceName, initialValue, allocationSize));
  	}
docs: Add a sequence definition DDL, note: some dialects do not support sequence
  
  @param name
  The name of sequence Java object itself
  @param sequenceName
  the name of the sequence will created in database
  @param initialValue
  The initial value
  @param allocationSize
  The allocationSize