java.util.Collections

is imported to:

.   bluej
.   bluej.collect
.   bluej.compiler
.   bluej.debugger.gentype
.   bluej.debugger.jdi
.   bluej.debugmgr
.   bluej.debugmgr.codepad
.   bluej.debugmgr.inspector
.   bluej.debugmgr.objectbench
.   bluej.editor.moe
.   bluej.editor.stride
.   bluej.groupwork.actions
.   bluej.groupwork.git
.   bluej.groupwork.svn
.   bluej.groupwork.ui
.   bluej.parser
.   bluej.parser.entity
.   bluej.parser.nodes
.   bluej.pkgmgr
.   bluej.pkgmgr.target.role
.   bluej.runtime
.   bluej.stride.framedjava.ast
.   bluej.stride.framedjava.convert
.   bluej.stride.framedjava.elements
.   bluej.stride.framedjava.errors
.   bluej.stride.framedjava.frames
.   bluej.stride.framedjava.slots
.   bluej.stride.generic
.   bluej.stride.operations
.   bluej.stride.slots
.   bluej.utility
.   bluej.utility.javafx
.   greenfoot.export.mygame
.   greenfoot.guifx.classes
.   greenfoot.platforms.ide
.   greenfoot.util
.   greenfoot.vmcomm
.   threadchecker