title: Check if a location on a leaflet map is a marker or not
body: <p>I want to determine if there already is a marker at a certain lat and lng</p>
  
  <p>The only method I found when doing research was <code>mymap.hasLayer(marker)</code></p>
  
  <p>But I don't want to and can't use a marker variable since I only have the location (lat, long)</p>
  
  <p>I need to know this because some markers will overlap and the only way I know how to solve that is check if a marker exists on that location and if it does the modify it add info to it</p>