package com.atlassian.plugin.loaders.classloading;
   
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   
   import java.util.Collection;
   import java.util.Collections;
   
   /**
   * A {@link Scanner} which never finds anything.
   *
   * @since 3.0.16
   */
  public class EmptyScanner implements Scanner {
      private static final Logger log = LoggerFactory.getLogger(EmptyScanner.class);
  
      public Collection<DeploymentUnit> scan() {
          return Collections.emptyList();
      }
  
      public Collection<DeploymentUnit> getDeploymentUnits() {
          return Collections.emptyList();
      }
  
      public void reset() {
          // Nothing to reset
      }
  
      public void remove(final DeploymentUnit unit) {
          // Nothing to remove, but the caller shouldn't be trying really, so WARN - it's
          // recoverable, but probably indicates a bug
          log.warn("EmptyScanner.remove called for {}", unit);
      }
  }