code: static File getLibDir() throws IOException {
          String mdwHome = System.getenv("MDW_HOME");
          if (mdwHome == null)
              mdwHome = System.getProperty("mdw.home");
          if (mdwHome == null)
              throw new IOException("Missing environment variable: MDW_HOME");
          File mdwDir = new File(mdwHome);
          if (!mdwDir.isDirectory())
              throw new IOException("MDW_HOME is not a directory: " + mdwDir.getAbsolutePath());
          File libDir = new File (mdwDir + "/lib");
          if (!libDir.exists() && !libDir.mkdirs())
              throw new IOException("Cannot create lib dir: " + libDir.getAbsolutePath());
          return libDir;
      }
docs: Creates libDir and throws IOException if unable.