input: Write a python function to summarize text into two sentences.
  assert summarize_text("Natural language processing (NLP) is a subfield of linguistics, computer science, and artificial intelligence concerned with the interactions between computers and human language. As such, NLP is related to the area of human-computer interaction. Many challenges in NLP involve natural language understanding, natural language generation frequently from formal, machine-readable logical forms, connecting language and machine perception, managing human- computer dialog systems, or some combination thereof.") == "Natural language processing (NLP) is a subfield of linguistics, computer science, and artificial intelligence concerned with the interactions between computers and human language. As such, NLP is related to the area of human-computer interaction."
  assert summarize_text("The quick brown fox jumps over the lazy dog. The dog was not amused. The fox then ran away. The dog continued to sleep. This is a test sentence to see if the summarizer can summarize correctly.") == "The quick brown fox jumps over the lazy dog. The dog was not amused."
  assert summarize_text("Python is a high-level, interpreted, general-purpose programming language. Its design philosophy emphasizes code readability with the use of significant indentation. Python is dynamically typed and garbage-collected. It supports multiple programming paradigms, including structured (particularly procedural), object-oriented and functional programming.") == "Python is a high-level, interpreted, general-purpose programming language. Its design philosophy emphasizes code readability with the use of significant indentation."
output: def summarize_text(text):
      sentences = text.split('. ')
      summary = '. '.join(sentences[:2])
      if not summary.endswith('.'):
          summary += '.'
      return summary