code: public DataSource<StringValue> readTextFileWithValue(String filePath) {
  		Preconditions.checkNotNull(filePath, "The file path may not be null.");
  
  		return new DataSource<>(this, new TextValueInputFormat(new Path(filePath)), new ValueTypeInfo<>(StringValue.class), Utils.getCallLocationName());
  	}
docs: Creates a {@link DataSet} that represents the Strings produced by reading the given file line wise.
  This method is similar to {@link #readTextFile(String)}, but it produces a DataSet with mutable
  {@link StringValue} objects, rather than Java Strings. StringValues can be used to tune implementations
  to be less object and garbage collection heavy.
  
  <p>The file will be read with the UTF-8 character set.
  
  @param filePath The path of the file, as a URI (e.g., "file:///some/local/file" or "hdfs://host:port/file/path").
  @return A {@link DataSet} that represents the data read from the given file as text lines.