This site will look much better in a browser that supports web standards, but it is accessible to any browser or Internet device.
In SequenceableCollection you can find:
copyWith: newElement
"Answer a copy of the receiver that is 1 bigger
"than the receiver and has newElement at the last element."
"code omitted"
An example of its use is:
|newString|
newString := 'Endin' copyWith: $g.
^newString "newString references 'Ending'"