def callsites(classname_or_fullname, methodname = nil)
      rawsites = raw_data_relative.first[expand_name(classname_or_fullname, methodname)]
      return nil unless rawsites
      ret = {}
      # could be a job for inject but it's slow and I don't mind the extra loc
      rawsites.each_pair do |backtrace, count|
        ret[CallSite.new(backtrace)] = count
      end
      ret
    end
def callsites(classname_or_fullname, methodname = nil)
      rawsites = raw_data_relative.first[expand_name(classname_or_fullname, methodname)]
      return nil unless rawsites
      ret = {}
      # could be a job for inject but it's slow and I don't mind the extra loc
      rawsites.each_pair do |backtrace, count|
        ret[CallSite.new(backtrace)] = count
      end
      ret
    end
Returns a hash with <tt>CallSite => call count</tt> associations or +nil+
 Can be called in two ways:
   analyzer.callsites("Foo#f1")         # instance method
   analyzer.callsites("Foo.g1")         # singleton method of the class
 or
   analyzer.callsites("Foo", "f1")
   analyzer.callsites("#<class:Foo>", "g1")