When you have multiple test runs using pipelines, it would be super awesome to be able to annotate the different test runs with a name to allow differentiation, e.g.

node('windows') {
  ...
  junit testResults:'target/tests.xml' testRunName: 'windows'
}
node('linux') {
  ...
  junit testResults:'target/tests.xml' testRunName: 'linux'
}

This way you can tell which test run the tests came from.

The following screenshot illustrates how this would apply (by basically appending the test run name to each case)