LSP crash stack trace

[apiology]

No reason to think this is a regression:

[WARN] Error processing request: [NoMethodError] undefined method '+' for nil
[WARN] /Users/broz/src/solargraph/lib/solargraph/parser/parser_gem/class_methods.rb:60:in 'block in Solargraph::Parser::ParserGem::ClassMethods#references'
/Users/broz/src/solargraph/lib/solargraph/parser/parser_gem/class_methods.rb:65:in 'block in Solargraph::Parser::ParserGem::ClassMethods#references'
/Users/broz/src/solargraph/lib/solargraph/parser/parser_gem/class_methods.rb:62:in 'Array#map'
/Users/broz/src/solargraph/lib/solargraph/parser/parser_gem/class_methods.rb:62:in 'Solargraph::Parser::ParserGem::ClassMethods#references'
/Users/broz/src/solargraph/lib/solargraph/source.rb:174:in 'Solargraph::Source#references'
/Users/broz/src/solargraph/lib/solargraph/source_map.rb:139:in 'Solargraph::SourceMap#references'
/Users/broz/src/solargraph/lib/solargraph/library.rb:256:in 'block in Solargraph::Library#references_from'
/Users/broz/src/solargraph/lib/solargraph/library.rb:255:in 'Array#each'
/Users/broz/src/solargraph/lib/solargraph/library.rb:255:in 'Solargraph::Library#references_from'
/Users/broz/src/solargraph/lib/solargraph/language_server/host.rb:586:in 'Solargraph::LanguageServer::Host#references_from'
/Users/broz/src/solargraph/lib/solargraph/language_server/message/text_document/document_highlight.rb:6:in 'Solargraph::LanguageServer::Message::TextDocument::DocumentHighlight#process'
/Users/broz/src/solargraph/lib/solargraph/language_server/host.rb:105:in 'Solargraph::LanguageServer::Host#receive'
/Users/broz/src/solargraph/lib/solargraph/language_server/host/message_worker.rb:70:in 'Solargraph::LanguageServer::Host::MessageWorker#tick'
/Users/broz/src/solargraph/lib/solargraph/language_server/host/message_worker.rb:59:in 'block in Solargraph::LanguageServer::Host::MessageWorker#start'

[apiology]

Saw it again:

[WARN] Error processing request: [NoMethodError] undefined method '+' for nil
[WARN] /Users/broz/src/solargraph/lib/solargraph/parser/parser_gem/class_methods.rb:62:in 'block in Solargraph::Parser::ParserGem::ClassMethods#references'
/Users/broz/src/solargraph/lib/solargraph/parser/parser_gem/class_methods.rb:68:in 'block in Solargraph::Parser::ParserGem::ClassMethods#references'
/Users/broz/src/solargraph/lib/solargraph/parser/parser_gem/class_methods.rb:64:in 'Array#map'
/Users/broz/src/solargraph/lib/solargraph/parser/parser_gem/class_methods.rb:64:in 'Solargraph::Parser::ParserGem::ClassMethods#references'
/Users/broz/src/solargraph/lib/solargraph/source.rb:183:in 'Solargraph::Source#references'
/Users/broz/src/solargraph/lib/solargraph/source_map.rb:138:in 'Solargraph::SourceMap#references'
/Users/broz/src/solargraph/lib/solargraph/library.rb:265:in 'block in Solargraph::Library#references_from'
/Users/broz/src/solargraph/lib/solargraph/library.rb:264:in 'Array#each'
/Users/broz/src/solargraph/lib/solargraph/library.rb:264:in 'Solargraph::Library#references_from'
/Users/broz/src/solargraph/lib/solargraph/language_server/host.rb:587:in 'Solargraph::LanguageServer::Host#references_from'
/Users/broz/src/solargraph/lib/solargraph/language_server/message/text_document/document_highlight.rb:6:in 'Solargraph::LanguageServer::Message::TextDocument::DocumentHighlight#process'
/Users/broz/src/solargraph/lib/solargraph/language_server/host.rb:105:in 'Solargraph::LanguageServer::Host#receive'
/Users/broz/src/solargraph/lib/solargraph/language_server/host/message_worker.rb:70:in 'Solargraph::LanguageServer::Host::MessageWorker#tick'
/Users/broz/src/solargraph/lib/solargraph/language_server/host/message_worker.rb:59:in 'block in Solargraph::LanguageServer::Host::MessageWorker#start'