diff_cov.diff

diff --git a/example.rb b/example.rb
index 088e788..8616fa6 100644
--- a/example.rb
+++ b/example.rb
@@ -1,3 +1,31 @@
 require 'coverage'
+module Coverage
+  module Extension
+    def pause; end
+    def reset; end
+
+    def resume
+      @baseline = peek_result
+    end
+
+    def subtract old, new
+      new.each_pair.with_object({}) do |(k, v), hash|
+        if old.key? k
+          prev_cov = old[k]
+          hash[k] = v.map.with_index { |info, i| info ? info - prev_cov[i] : info }
+        else
+          hash[k] = v.dup
+        end
+      end
+    end
+
+    def result
+      return super unless @baseline
+      subtract @baseline, peek_result
+    end
+  end
+
+  class << self; self; end.prepend Extension
+end
 Coverage.start
 require './covercheck'