title: How can I create configurable custom hypothesis strategies which use `builds()`?
body: <p>I created custom Hypothesis strategies using <a href="http://hypothesis.readthedocs.io/en/latest/data.html?highlight=builds#hypothesis.strategies.builds" rel="nofollow noreferrer"><code>builds()</code></a> and <a href="http://hypothesis.readthedocs.io/en/latest/data.html#composite-strategies" rel="nofollow noreferrer"><code>@composite</code></a> (the design is inspired by <a href="http://hypothesis.readthedocs.io/en/latest/examples.html#how-not-to-sort-by-a-partial-order" rel="nofollow noreferrer">this example from the docs</a>). The strategies are designed similar to the pseudo code below:</p>
  
  <pre><code># strategies.py
  
  from hypothesis.strategies import builds, composite, draw, floats, integers
  
  class SutConfiguration:
      """ Data which represents the configuration of the system under test. """
      def __init__(self, integer, float):
          self.integer = integer
          self.float = float
  
  # custom strategy which uses builds()
  SutConfigurationStrategy = builds(
      SutConfiguration,
      integer=integers(min_value=APP_SPECIFIC_INT_MIN, max_value=APP_SPECIFIC_INT_MAX),
      float=floats(min_value=APP_SPECIFIC_FLOAT_MIN, max_value=APP_SPECIFIC_FLOAT_MAX),
  )
  
  @composite
  def overall_test_configuration(draw, sut_st=SutConfigurationStrategy, env_st=SutEnvironmentStrategy):
      """Custom strategy which uses draw."""
      sut_config = draw(sut_st)
      env_config = draw(env_st)
      return (sut_config, rc_stereomatching_config, env_config)
  </code></pre>
  
  <p>The strategy is uses as usual e.g. using <code>unittest</code> as test runner:</p>
  
  <pre><code># test.py
  
  import unittest
  from &lt;package&gt;.strategies import overall_test_configuration
  
  class TestSut(unittest.TestCase):
      """Class containing several tests for the system under test."""
      @given(overall_test_configuration())
      def test_something():
          """Test which uses overall_test_configuration"""
          ...
  </code></pre>
  
  <p>Now I would like to make the strategies configurable to the actual application to define e.g. <code>min_value</code> in <code>integers(min_value=APP_SPECIFIC_INT_MIN, ...)</code> when defining the test function. This can be done for <code>@composite</code> strategies via agruments like <a href="https://github.com/knyghty/hotwo/blob/0436e63df7e2d9594a6ac445df357d7e21d59c2c/accounts/strategies.py#L12" rel="nofollow noreferrer">done here</a>. But how can I make the strategies which use <code>builds()</code> configurable?</p>