<｜begin▁of▁sentence｜>### Instruction:
Given a set of convex hulls, where each hull is represented by a list of points that define the hull, how can we visualize these hulls using the HullCollection's draw method?
### Response:
from matplotlib import pyplot as plt
from matplotlib.patches import Polygon
from matplotlib.collections import PatchCollection

class HullCollection:
    def __init__(self, hulls):
        self.hulls = hulls

    def draw(self, ax=None):
        if ax is None:
            ax = plt.gca()
        patches = []
        for hull in self.hulls:
            polygon = Polygon(hull, True)
            patches.append(polygon)
        p = PatchCollection(patches, alpha=0.4)
        ax.add_collection(p)
        plt.show()

# Example usage:
# Suppose we have a list of hulls (list of points defining the hulls)
hulls_points = [ [(0,0), (2,0), (1,2)], [(4,4), (6,4), (5,6)] ]
hull_collection = HullCollection(hulls_points)
fig, ax = plt.subplots()
hull_collection.draw(ax)
<|EOT|>
