if {![package vsatisfies [package provide Tcl] 8.5]} {return}

package ifneeded tcl::chan::core 1   [list source [list [file join $dir core.tcl]]]
package ifneeded tcl::chan::events 1 [list source [list [file join $dir events.tcl]]]

if {![package vsatisfies [package provide Tcl] 8.6]} {return}

package ifneeded tcl::transform::core 1 [list source [list [file join $dir transformcore.tcl]]]