Base:
method
AnalyzeSemanticModel
Microsoft.CodeAnalysis.RemoveUnnecessaryImports.AbstractRemoveUnnecessaryImportsDiagnosticAnalyzer<TSyntaxNode>.AnalyzeSemanticModel(Microsoft.CodeAnalysis.Diagnostics.SemanticModelAnalysisContext, Microsoft.CodeAnalysis.SyntaxTree, System.Threading.CancellationToken)