Output correct class name in custom inspect string

lib/jekyll/collection.rb

@@ -153,7 +153,7 @@ module Jekyll
     #
     # Returns the inspect string
     def inspect
-      "#<Jekyll::Collection @label=#{label} docs=#{docs}>"
+      "#<#{self.class} @label=#{label} docs=#{docs}>"
     end
 
     # Produce a sanitized label name

lib/jekyll/document.rb

@@ -295,7 +295,7 @@ module Jekyll
     #
     # Returns the inspect string for this document.
     def inspect
-      "#<Jekyll::Document #{relative_path} collection=#{collection.label}>"
+      "#<#{self.class} #{relative_path} collection=#{collection.label}>"
     end
 
     # The string representation for this document.

lib/jekyll/excerpt.rb

@@ -77,7 +77,7 @@ module Jekyll
 
     # Returns the shorthand String identifier of this doc.
     def inspect
-      "<Excerpt: #{id}>"
+      "<#{self.class} id=#{id}>"
     end
 
     def output

test/test_excerpt.rb

@@ -69,7 +69,7 @@ class TestExcerpt < JekyllUnitTest
 
     context "#inspect" do
       should "contain the excerpt id as a shorthand string identifier" do
-        assert_equal @excerpt.inspect, "<Excerpt: #{@excerpt.id}>"
+        assert_equal @excerpt.inspect, "<#{@excerpt.class} id=#{@excerpt.id}>"
       end
 
       should "return a string" do