title: How can I change style or unvisible openlayers cluster with 40,000+ data?
body: <p>Im using javascript and openlayers and I'm troubled in clustering bunch of data(40,000+).
  First, I made cluster with all my data by features with properties.
  example)</p>
  <p>id: &quot;61b989a38e8d3d422876f817&quot;
  name: &quot;LGU&quot;
  relative_alt: 100050
  rsrp: -74
  telecom: &quot;LGU&quot;
  visibility: 1</p>
  <p>here is my question!
  I want to disable or change style to null whatever unvisible features, with my limit.
  <a href="https://i.stack.imgur.com/PO7MT.png" rel="nofollow noreferrer">example</a></p>
  <p>like this code. but if I try this, it took so long.</p>
  <p>Thank you!</p>