code: public static Loader csv(Reader reader, List<String> columns, List<String> dimensions, String timestampDimension) {
          return new CSVLoader(reader, columns, dimensions, timestampDimension);
      }
docs: CSVLoader implementation of the Loader
  
  @param reader             A Reader opened to the CSV file
  @param columns            List of columns in the CSV
  @param dimensions         List of dimensions to index
  @param timestampDimension Timestamp dimension
  @return A new CSVLoader to the CSV file specified by the reader