How to throttle matrix configurations in Jenkins declarative pipeline - jenkins

Question

I need to throttle Matrix configurations in Jenkins declarative pipeline. For now I have a simple matrix like that:
matrix {
axes {
axis {
name 'Test'
values 'Example1','Example2','Example3'
}
}
}
And I can run only five configuration in parallel. First of all I created a category:
And now I'm trying to use throttle job property and there I'm stuck. As I see here in order to use throttle matrix configurations we need to pass matrixOptions parameters that contains two properties throttleMatrixBuilds and throttleMatrixConfigurations.
options {
throttleJobProperty(
categories: ['ForTestMatrix'],
throttleEnabled: true,
throttleOption: 'category',
matrixOptions: ???
)
}
Could someone tell me how to pass an object with two properties as a parameter there?
UPD
I managed to run this code like that:
options {
throttleJobProperty(
categories: ['ForTestMatrix'],
throttleEnabled: true,
throttleOption: 'category',
matrixOptions: new hudson.plugins.throttleconcurrents.ThrottleMatrixProjectOptions(false, true)
)
}
But when I start this job I see in blue ocean that all the matrix configurations start at once. Does anyone have ideas why throttling doesn't work correctly?

Answer 1

See Throttle Concurrent Builds:
Unsupported use cases
This section contains links to the use cases which are not supported.
Throttling of code blocks without a node() definition
...
Throttling Pipeline via job properties
Starting in throttle-concurrents-2.0, using this option is not recommended. Use the throttle() step instead.
The following pipeline:
pipeline {
agent any
stages {
stage('Matrix') {
matrix {
axes {
axis {
name 'Example'
values 'Example 1','Example 2','Example 3'
}
}
stages {
stage('Test') {
steps {
throttle(['ForTestMatrix']) {
node( 'master' ) {
sh 'set +x; date; sleep 5; date'
}
} // throttle
} // steps
} // stage 'Test'
} // stages
} // matrix
} // stage 'Matrix'
} // stages
} // pipeline
gives this output:
...
[Matrix - Example = 'Example 1'] + set +x
Fri Oct 22 15:54:01 GMT 2021
Fri Oct 22 15:54:06 GMT 2021
...
[Matrix - Example = 'Example 2'] + set +x
Fri Oct 22 15:54:06 GMT 2021
Fri Oct 22 15:54:12 GMT 2021
...
[Matrix - Example = 'Example 3'] + set +x
Fri Oct 22 15:54:12 GMT 2021
Fri Oct 22 15:54:17 GMT 2021
...