optimal_sink_wrap: optimal_sink_wrap
In rzgross/uRbanmatching:

Given a vector of sink values, generates an optimal match for each.

1	optimal_sink_wrap(dist_mat, treat_vec, n_sinks, tol_val, weight_vec = NULL)

`dist_mat`	Matrix of pairwise distances.
`treat_vec`	Vector representing all subjects; 0 for control, 1 for treated.
`n_sinks`	Default NULL, vector of sink values to use.
`tol_val`	Tolerance for solving optimal matches (how far from the true optimal value is acceptable). Speed with large value, accuracy with small.
`weight_vec`	Default `NULL`: optionally supply the weight vector used to generate `dist_mat` and it'll be returned in the `match_list` generated from this function.