package com.atlassian.plugins.rest.module.jersey;
   
   import java.util.List;
   import java.util.Map;
   
   class HeaderHelper {
       static String getSingleHeaderValue(final Map<String, List<String>> headerMap, final String headerName, final String defaultValue) {
           String value = defaultValue;
           List<String> contentTypeHeaders = headerMap.get(headerName);
          if (contentTypeHeaders != null && contentTypeHeaders.size() == 1) {
              value = contentTypeHeaders.get(0);
          }
          return value;
      }
  }