Fix yardstick coverage

lib/mutant/matcher/filter.rb

@@ -4,14 +4,13 @@ module Mutant
     class Filter < self
       include Concord.new(:matcher, :predicate)
 
-      # Return new matcher
+      # New matcher
       #
-      # @return [Matcher] matcher
+      # @param [Matcher] matcher
       #
       # @return [Matcher]
       #
       # @api private
-      #
       def self.build(matcher, &predicate)
         new(matcher, predicate)
       end

lib/mutant/parallel/master.rb

@@ -39,6 +39,8 @@ module Mutant
       #
       # rubocop:disable MethodLength
       #
+      # @return [undefined]
+      #
       # @api private
       def run
         config.jobs.times do

lib/mutant/runner.rb

@@ -27,9 +27,9 @@ module Mutant
 
     # Run mutation analysis
     #
-    #  @return [undefined]
+    # @return [undefined]
     #
-    #  @api private
+    # @api private
     def run_mutation_analysis
       @result = run_driver(Parallel.async(mutation_test_config))
       reporter.report(@result)