code: @Override
  	public void configure(Configuration parameters) {
  
  		if (getFilePaths().length == 0) {
  			// file path was not specified yet. Try to set it from the parameters.
  			String filePath = parameters.getString(FILE_PARAMETER_KEY, null);
  			if (filePath == null) {
  				throw new IllegalArgumentException("File path was not specified in input format or configuration.");
  			} else {
  				setFilePath(filePath);
  			}
  		}
  
  		if (!this.enumerateNestedFiles) {
  			this.enumerateNestedFiles = parameters.getBoolean(ENUMERATE_NESTED_FILES_FLAG, false);
  		}
  	}
docs: Configures the file input format by reading the file path from the configuration.
  
  @see org.apache.flink.api.common.io.InputFormat#configure(org.apache.flink.configuration.Configuration)