在Behave框架中，可以使用execute_steps方法来模拟场景大纲输出。代码示例如下：

from behave import step, given, when, then, use_step_matcher
from behave.model import Table

use_step_matcher("parse")

@given("I have a list of numbers")
def step_impl(context):
    context.numbers = [1, 2, 3, 4, 5]

@when("I add {number:d} to each number in the list")
def step_impl(context, number):
    for i in range(len(context.numbers)):
        context.numbers[i] += number
    # Use execute_steps to mimic scenario outline output
    context.execute_steps(f"""
        Then the list should be:
            | numbers |
            | {" | ".join(str(n) for n in context.numbers)} |
    """)

@then("the list should be:")
def step_impl(context):
    expected = [list(map(int, row)) for row in context.table]
    assert context.numbers == expected[0]

在这个例子中，当执行'I add 2 to each number in the list”的步骤时，使用execute_steps方法来模拟输出场景大纲。执行该步骤后，将会执行与'the list should be:”步骤相同的表格验证步骤，以检查预期输出是否与实际输出匹配。