def defsite(classname_or_fullname, methodname = nil)
      file, line = raw_data_relative[1][expand_name(classname_or_fullname, methodname)]
      return nil unless file && line
      DefSite.new(file, line)
    end
def defsite(classname_or_fullname, methodname = nil)
      file, line = raw_data_relative[1][expand_name(classname_or_fullname, methodname)]
      return nil unless file && line
      DefSite.new(file, line)
    end
Returns a DefSite object corresponding to the given method
 Can be called in two ways:
   analyzer.defsite("Foo#f1")         # instance method
   analyzer.defsite("Foo.g1")         # singleton method of the class
 or
   analyzer.defsite("Foo", "f1")
   analyzer.defsite("#<class:Foo>", "g1")