How to use the cucumber-expressions.RegularExpression function in cucumber-expressions

this.runtime = (matcher, implementation) => {
      let expression;
      if (matcher instanceof RegExp) {
        expression = new RegularExpression(
          matcher,
          this.options.parameterTypeRegistry
        );
      } else {
        expression = new CucumberExpression(
          matcher,
          this.options.parameterTypeRegistry
        );
      }

      this.definitions.push({
        implementation,
        expression,
        featureName: window.currentFeatureName || "___GLOBAL_EXECUTION___"
      });
    };

private registerStepDefinition(
    expression: string | RegExp,
    body: AnyBody
  ): void {
    const sourceReference = getSourceReference(new Error().stack)
    const expr =
      typeof expression === 'string'
        ? new CucumberExpression(expression, this.parameterTypeRegistry)
        : new RegularExpression(expression, this.parameterTypeRegistry)
    const stepDefinition = new ExpressionStepDefinition(
      this.newId(),
      expr,
      sourceReference,
      body
    )
    this.stepDefinitions.push(stepDefinition)
  }

({ code, line, options, pattern, uri }) => {
        const expression =
          typeof pattern === 'string'
            ? new CucumberExpression(pattern, this.parameterTypeRegistry)
            : new RegularExpression(pattern, this.parameterTypeRegistry)
        const wrappedCode = this.wrapCode({
          code,
          wrapperOptions: options.wrapperOptions,
        })
        return new StepDefinition({
          code: wrappedCode,
          expression,
          id: this.newId(),
          line,
          options,
          pattern,
          unwrappedCode: code,
          uri,
        })
      }
    )