docstr: Create Prometheus client.
  
  :param api_url: URL of Prometheus server.
  :param http: Requests Session to use for requests. Optional.
docstr_tok: ["Create","Prometheus","client",".",":","param","api_url",":","URL","of","Prometheus","server",".",":","param","http",":","Requests","Session","to","use","for","requests",".","Optional","."]
code: def __init__(
      self, api_url: str, http: Optional[requests.Session] = None
  ):
      """
      Create Prometheus client.
  
      :param api_url: URL of Prometheus server.
      :param http: Requests Session to use for requests. Optional.
      """
      self.http = http or requests.Session()
      self.api_url = api_url
  
file_path: BigDL/python/chronos/src/bigdl/chronos/data/utils/prometheus_df.py
imports: import datetime
  import json
  from typing import Optional, Union
  from urllib.parse import urljoin
  import numpy
  import pandas
  import requests
  from bigdl.nano.utils.common import invalidInputError
label_desc: Use image node_id 1 to create a new Prometheus object  with example: obj = Prometheus(api_url, http)