Fix assets tests by passing undefined rather than null
Fix assets tests by passing undefined rather than null

OmniSharp/omnisharp-vscode,OmniSharp/omnisharp-vscode,gregg-miskelly/omnisharp-vscode,gregg-miskelly/omnisharp-vscode,gregg-miskelly/omnisharp-vscode,gregg-miskelly/omnisharp-vscode,OmniSharp/omnisharp-vscode,OmniSharp/omnisharp-vscode,OmniSharp/omnisharp-vscode