code: function getCompletionEntryDisplayNameForSymbol(symbol, target, performCharacterChecks, location) {
              var displayName = ts.getDeclaredName(program.getTypeChecker(), symbol, location);
              if (displayName) {
                  var firstCharCode = displayName.charCodeAt(0);
                  // First check of the displayName is not external module; if it is an external module, it is not valid entry
                  if ((symbol.flags & 1920 /* Namespace */) && (firstCharCode === 39 /* singleQuote */ || firstCharCode === 34 /* doubleQuote */)) {
                      // If the symbol is external module, don't show it in the completion list
                      // (i.e declare module "http" { const x; } | // <= request completion here, "http" should not be there)
                      return undefined;
                  }
              }
              return getCompletionEntryDisplayName(displayName, target, performCharacterChecks);
          }
docs: Get the name to be display in completion from a given symbol.
  
  @return undefined if the name is of external module otherwise a name with striped of any quote