code: public String findRelative(String base, String uri) throws ResourceNotFoundException, IOException {
  
  		String path = getPath(base, uri);
  
  		String source = resolveAndNormalize(path);
  
  		if (source != null) {
  			return source;
  		}
  
  		// Try to find partial import (_identifier.scss)
  		path = PathNormalizer.getParentPath(path) + "_" + PathNormalizer.getPathName(path);
  
  		source = resolveAndNormalize(path);
  
  		if (source != null) {
  			return source;
  		}
  
  		return resolveAndNormalize(uri);
  
  	}
docs: Return the content of the resource using the base path and the relative
  URI
  
  @param base
  the base path
  @param uri
  the relative URI
  @return the content of the resource using the base path and the relative
  URI
  @throws ResourceNotFoundException
  if the resource is not found
  @throws IOException
  if an IOException occurs