code: public EventPattern append( EventSet esi, int minRepeats, Integer maxRepeats ) {
  		glob.add( new EventPatternPart( esi, minRepeats, maxRepeats) );
  		return this;
  	}
docs: Appends possible occurrence(s) of {@code esi} to the pattern.
  
  @param minRepeats minimum number of repeats.
  @param maxRepeats maximum number of repeats, or {@code null} if unlimited.
  @param esi the EventSet, that one if its members should occur (really, an OR).
  @return {@code this}, to allow call chaining.