René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"IndexError in signature.py on textDocument/signatureHelp","articleBody":"I'm using pyls via [coc.nvim](https://github.com/neoclide/coc.nvim), and when it attempts to grab the signature of a class method, it's throwing an IndexError on this line:\r\n\r\nhttps://github.com/palantir/python-language-server/blob/d7fb817e8f992bd5c6a287f5afb5e999a1e29449/pyls/plugins/signature.py#L24\r\n\r\nIt looks like in this case `s.docstring()` is somehow not returning a string, which causes `splitlines()` to not return an array, and `[0]` causes the error.\r\n\r\nThis was easy to mitigate by just catching that error and returning returning `.splitlines()` without the index, but I wanted to flag it here in case your team might have a better idea for why/when that wouldn't return an array, and what the right way to mitigate it is.\r\n\r\n![image](https://user-images.githubusercontent.com/1016999/49701095-c0f90e00-fbb5-11e8-9868-1e1131a4f45c.png)\r\n","author":{"url":"https://github.com/mike-hearn","@type":"Person","name":"mike-hearn"},"datePublished":"2018-12-09T18:30:24.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/459/python-language-server/issues/459"}