code: public DataSource<String> readTextFile(String filePath, String charsetName) {
  		Validate.notNull(filePath, "The file path may not be null.");
  
  		TextInputFormat format = new TextInputFormat(new Path(filePath));
  		format.setCharsetName(charsetName);
  		return new DataSource<String>(this, format, BasicTypeInfo.STRING_TYPE_INFO );
  	}
docs: Creates a DataSet that represents the Strings produced by reading the given file line wise.
  The {@link java.nio.charset.Charset} with the given name will be used to read the files.
  
  @param filePath The path of the file, as a URI (e.g., "file:///some/local/file" or "hdfs://host:port/file/path").
  @param charsetName The name of the character set used to read the file.
  @return A DataSet that represents the data read from the given file as text lines.