EndLine sets the optional parameter "endLine": The index of the last line from which to start importing, exclusive. Thus, the number of imported lines is endLine - startLine. If this parameter is not provided, the file will be imported until the last line of the file. If endLine is negative, then the imported content will exclude the last endLine lines. That is, if endline is negative, no line will be imported whose index is greater than N + endLine where N is the number of lines in the file, and the number of imported lines will be N + endLine - startLine.