package com.atlassian.marketplace.client.http;
   
   import java.util.Map;
   
   import com.google.common.collect.ImmutableMap;
   
   /**
    * Allows the caller to attach custom request headers to all client requests.
    * @since 2.0.0
   */
  public interface RequestDecorator
  {
      /**
       * Returns a map of header names and values that should be added to outgoing
       * Marketplace requests.
       */
      public Map<String, String> getRequestHeaders();
      
      public static abstract class Instances
      {
          /**
           * Returns a {@link RequestDecorator} instance that always adds the same constant header values.
           * @param headers  a map of header names and values
           */
          public static RequestDecorator forHeaders(Map<String, String> headers)
          {
              final ImmutableMap<String, String> immutableHeaders = ImmutableMap.copyOf(headers);
              return new RequestDecorator()
              {
                  @Override
                  public Map<String,String> getRequestHeaders()
                  {
                      return immutableHeaders;
                  }
              };
          }
      }
  }