<<rule>> Delete: Multiplicity-One Containment Reference
<<preserve>>
fromContainedClass : EClass
<<preserve>>
fromContainerClass : EClass
<<delete>>
oldContainmentReference : EReference
<<delete>> upperBound = "1"
<<delete>> containment = "true"
<<forbid, pre>>
preContainerReference : EReference
<<delete>>
eType
<<forbid, pre>>
eOpposite
<<forbid, pre>>
eOpposite
<<delete>>
eContainingClass
eStructuralFeatures