def merge_resultsets(result1, result2)
      (result1.keys | result2.keys).each_with_object({}) do |filename, merged|
        file1 = result1[filename]
        file2 = result2[filename]
        merged[filename] = merge_file_coverage(file1, file2)
      end
    end
def merge_resultsets(result1, result2)
      (result1.keys | result2.keys).each_with_object({}) do |filename, merged|
        file1 = result1[filename]
        file2 = result2[filename]
        merged[filename] = merge_file_coverage(file1, file2)
      end
    end
Merges two Coverage.result hashes