If there are exactly four dispensers, and at least of them are chrome.
return dispensers ;return #1 that are chrome ;return the  number of  #1 ;return the  number of  #2 ;return if  #3 is equal to  four ;return if  #4 is at least one ;return if  both  #5 and #6 is true
['select', 'filter', 'aggregate', 'aggregate', 'boolean', 'boolean', 'boolean']