1.62.6 Dictionary: dictionary testing

includes: anObject

Answer whether the receiver contains anObject as one of its values

includesAssociation: anAssociation

Answer whether the receiver contains the key which is anAssociation's key and its value is anAssociation's value

includesKey: key

Answer whether the receiver contains the given key

occurrencesOf: aValue

Answer whether the number of occurrences of aValue as one of the receiver's values