zoom.extent([extent]) If extent is specified, sets the viewport extent to the specified array of points [[x0
zoom.interpolate([interpolate]) If interpolate is specified, sets the interpolation factory for zoom transitions
d3.zoomTransform(node) Returns the current transform for the specified node. Note that node should typically
transform.scale(k) Returns a transform whose scale k₁ is equal to k₀ × k, where k₀
transform.invertX(x) Returns the inverse transformation of the specified x-coordinate, (x - tx)
zoom.scaleTo(selection, k) If selection is a selection,
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