graph.getSubgraph(cells [, opt])

Return an array of cells that result from finding elements/links that are connected to any of the cells in the cells array. This function loops over cells and if the current cell is a link, it collects its source/target elements; if it is an element, it collects its incoming and outgoing links if both the link ends (source/target) are in the cells array. For example, for a single element, the result is that very same element. For two elements connected with a link: A --- L ---> B, the result of getSubgraph([A, B]) is [A, L, B] and the result of getSubgraph([L]) is also [A, L, B].
If opt.deep is true take into account all the embedded cells too when finding neighboring links/elements.