code: function checkCRS(crs) {
      if (crs.type === 'name') {
          if (crs.properties && crs.properties.name) {
              return true;
          } else {
              throw new Error('Invalid CRS. Properties must contain "name" key');
          }
      } else if (crs.type === 'link') {
          if (crs.properties && crs.properties.href && crs.properties.type) {
              return true;
          } else {
              throw new Error('Invalid CRS. Properties must contain "href" and "type" key');
          }
      } else {
          throw new Error('Invald CRS. Type attribute must be "name" or "link"');
      }
    }
docs: Verify that the structure of CRS object is valid