“…For example, Nitsch [Nit57], Heins [Hei62] and Yamada [Yam88] proved that an isolated singularity of a hyperbolic metric is either a conical singularity or a cusp one, and Heins [Hei62], Mcowen [McO88] and Troyanov [Tro91] independently gave a necessary and sufficient condition for the existence of a unique hyperbolic metric, which has the prescribed conical or cusp singularities, on a compact Riemann surface. Among all the research on singular metrics on Riemann surfaces, developing maps, due to [Bry87,UY00,Ere04], prove to be a very useful tool. By considering the monodromy of developing maps in [CWWX15], Chen and coauthors constructed a new class of cone spherical metrics.…”