langchain/llms/anthropic.py/Anthropic/_wrap_prompt
class Anthropic:    def _wrap_prompt(self, prompt: str) -> str:
        if not self.HUMAN_PROMPT or not self.AI_PROMPT:
            raise NameError("Please ensure the anthropic package is loaded")

        if prompt.startswith(self.HUMAN_PROMPT):
            return prompt  # Already wrapped.

        # Guard against common errors in specifying wrong number of newlines.
        corrected_prompt, n_subs = re.subn(r"^\n*Human:", self.HUMAN_PROMPT, prompt)
        if n_subs == 1:
            return corrected_prompt

        # As a last resort, wrap the prompt ourselves to emulate instruct-style.
        return f"{self.HUMAN_PROMPT} {prompt}{self.AI_PROMPT} Sure, here you go:\n"