# File lib/rake.rb, line 420
420:     def investigation
421:       result = "------------------------------\n"
422:       result << "Investigating #{name}\n" 
423:       result << "class: #{self.class}\n"
424:       result <<  "task needed: #{needed?}\n"
425:       result <<  "timestamp: #{timestamp}\n"
426:       result << "pre-requisites: \n"
427:       prereqs = @prerequisites.collect {|name| application[name]}
428:       prereqs.sort! {|a,b| a.timestamp <=> b.timestamp}
429:       prereqs.each do |p|
430:         result << "--#{p.name} (#{p.timestamp})\n"
431:       end
432:       latest_prereq = @prerequisites.collect{|n| application[n].timestamp}.max
433:       result <<  "latest-prerequisite time: #{latest_prereq}\n"
434:       result << "................................\n\n"
435:       return result
436:     end