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: text_spec.rb
    path of file: ./repos/prawn/spec/prawn
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require 'spec_helper'

describe Prawn::Text do
  describe 'NBSP' do
    it 'is defined' do
      expect(Prawn::Text::NBSP).to eq("\u00a0")
    end
  end

  describe '#height_of' do
    let(:pdf
    
    def add_unicode_fonts(pdf)
      dejavu = "#{::Prawn::BASEDIR}/data/fonts/DejaVuSans.ttf"
      pdf.font_families.update(
        'dejavu' => {
          normal: dejavu,
          italic: dejavu,
          bold: dejavu,
          bold_italic: dejavu,
        },
      )
      pdf.fallback_fonts = ['dejavu']
    end