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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def hist2d(x, y, label=None, opacity=None):
 """2D Histogram. Parameters x : array-like, optional y : array-like, optional label : TODO, optional opacity : float, optional Returns ------- Chart """

    x = np.atleast_1d(x)
    y = np.atleast_1d(y)
    data = [go.Histogram2d(x=x, y=y, opacity=opacity, name=label)]
    return Chart(data=data)