You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: main.go
    path of file: ./repos/imagick/examples/text_effects
    
    the code of the file until where you have to start completion: // Port of http://members.shaw.ca/el.supremo/MagickWand/text_effects.htm to Go
package main

import "gopkg.in/gographics/imagick.v2/imagick"

// Given a pattern name (which MUST have a leading #) and a pattern file,
// set up a pattern URL for later reference in the specified drawing wand
// Currently only used in Text Effect 2
func setTilePattern(dw *imagick.DrawingWand, pattern_name, pattern_file string) {
	tw := imagick.NewMagickWand()

	tw.ReadImage(pattern_file)
	// Read the tile's width and height
	w := tw.GetImageWidth()
	h := tw.GetImageHeight()

	dw.PushPattern(pattern_name[1:], 0, 0, float64(w), float64(h))
	dw.Composite(imagick.COMPOSITE_OP_SRC_OVER, 0, 0, 0, 0, tw)
	dw.PopPattern()
	dw.SetFillPatternURL(pattern_name)
}

var dargs = []f
    
func textEffect1() {
	imagick.Initialize()
	defer imagick.Terminate()
	mw := imagick.NewMagickWand()
	dw := imagick.NewDrawingWand()
	pw := imagick.NewPixelWand()

	pw.SetColor("none")
	// Create a new transparent image
	mw.NewImage(350, 100, pw)
	// Set up a 72 point white font
	pw.SetColor("white")
	dw.SetFillColor(pw)
	dw.SetFont("Verdana-Bold-Italic")
	dw.SetFontSize(72)
	// Add a black outline to the text
	pw.SetColor("black")
	dw.SetStrokeColor(pw)
	// Turn antialias on - not sure this makes a difference
	dw.SetTextAntialias(true)
	// Now draw the text
	dw.Annotation(25, 65, "Magick")
	// Draw the image on to the mw
	mw.DrawImage(dw)
	// Trim the image down to include only the text
	mw.TrimImage(0)
	// equivalent to the command line +repage
	mw.ResetImagePage("")
	// Make a copy of the text image
	cw := mw.Clone()
	// Set the background colour to blue for the shadow
	pw.SetColor("blue")
	mw.SetImageBackgroundColor(pw)
	// Opacity is a real number indicating (apparently) percentage
	mw.ShadowImage(70, 4, 5, 5)
	// Composite the text on top of the shadow
	mw.CompositeImage(cw, imagick.COMPOSITE_OP_OVER, 5, 5)
	cw.Destroy()
	cw = imagick.NewMagickWand()

	// Create a new image the same size as the text image and put a solid colour
	// as its background
	pw.SetColor("rgb(125,215,255)")
	cw.NewImage(mw.GetImageWidth(), mw.GetImageHeight(), pw)
	// Now composite the shadowed text over the plain background
	cw.CompositeImage(mw, imagick.COMPOSITE_OP_OVER, 0, 0)
	// and write the result
	cw.WriteImage("text_shadow.png")
}