input: Write a function to generate a histogram using the data provided in Python. The function should plot the histogram with specified bins and display it. If the data is empty or None, the function should print "No data provided."
  import matplotlib.pyplot as plt
  
  def generate_histogram(data):
      if not data:
          print("No data provided.")
          return
      # plotting the histogram 
      plt.hist(data, bins = [0, 20, 40, 60, 80, 100, 120, 140, 160], edgecolor = 'black') 
        
      # x-axis label 
      plt.xlabel('Range of values') 
      # y-axis label 
      plt.ylabel('Number of Occurrences') 
      # plot title 
      plt.title('Histogram of data') 
        
      # function to show the plot 
      plt.show()
  
  assert generate_histogram([3, 5, 7, 2, 8, 10, 11, 65, 72, 81, 99, 100, 150]) is None
  assert generate_histogram([]) == "No data provided."
  assert generate_histogram(None) == "No data provided."
output: def generate_histogram(data):
      if not data:
          print("No data provided.")
          return
      plt.hist(data, bins=[0, 20, 40, 60, 80, 100, 120, 140, 160], edgecolor='black')
      plt.xlabel('Range of values')
      plt.ylabel('Number of Occurrences')
      plt.title('Histogram of data')
      plt.show()