A Flow File is a data record, which consists of a pointer to its content (payload) and attributes to support the content, that is associated with one or more provenance events. The attributes are key/value pairs that act as the metadata for the Flow File, such as the Flow File filename. Formatting of a FLOW file is done through Spacing and indentation which should be consistent throughout your code. Many developers choose to use 4-space or 2-space indentation. In FLOW, each nested statement (e.g., a statement following a '{' brace) should be indented exactly once more than the previous line's indentation.)