Query : How to draw square shaped markers in line graph.

I am trying to change the rounded markers to square shape in the line graph as shown in the image below..But didnot help..how can i acheive this effect?

Start by reviewing the Charts line-graph marker configuration and the linked screenshot to understand the requested square-marker effect. No source file or test is identified in the issue; the work is done when the line graph can display square-shaped markers and the behavior is covered by an appropriate check.

Written by the indexing model from the issue text.