code: def load_credentials(self, boto_session=None, profile_name=None):
          
          # Automatically load credentials from config or environment
          if not boto_session:
  
              # If provided, use the supplied profile name.
              if profile_name:
                  self.boto_session = boto3.Session(profile_name=profile_name, region_name=self.aws_region)
              elif os.environ.get('AWS_ACCESS_KEY_ID') and os.environ.get('AWS_SECRET_ACCESS_KEY'):
                  region_name = os.environ.get('AWS_DEFAULT_REGION') or self.aws_region
                  session_kw = {
                      "aws_access_key_id": os.environ.get('AWS_ACCESS_KEY_ID'),
                      "aws_secret_access_key": os.environ.get('AWS_SECRET_ACCESS_KEY'),
                      "region_name": region_name,
                  }
  
                  # If we're executing in a role, AWS_SESSION_TOKEN will be present, too.
                  if os.environ.get("AWS_SESSION_TOKEN"):
                      session_kw["aws_session_token"] = os.environ.get("AWS_SESSION_TOKEN")
  
                  self.boto_session = boto3.Session(**session_kw)
              else:
                  self.boto_session = boto3.Session(region_name=self.aws_region)
  
              logger.debug("Loaded boto session from config: %s", boto_session)
          else:
              logger.debug("Using provided boto session: %s", boto_session)
              self.boto_session = boto_session
  
          # use provided session's region in case it differs
          self.aws_region = self.boto_session.region_name
  
          if self.boto_session.region_name not in LAMBDA_REGIONS:
              print("Warning! AWS Lambda may not be available in this AWS Region!")
  
          if self.boto_session.region_name not in API_GATEWAY_REGIONS:
              print("Warning! AWS API Gateway may not be available in this AWS Region!")
docs: Load AWS credentials.
  
          An optional boto_session can be provided, but that's usually for testing.
  
          An optional profile_name can be provided for config files that have multiple sets
          of credentials.