class_docstr: An example of a KmsClient implementation with master keys
  managed by Hashicorp Vault KMS.
  See Vault documentation: https://www.vaultproject.io/api/secret/transit
  Not for production use!
docstr: Create a VaultClient instance.
  
  Parameters
  ----------
  kms_connection_config : KmsConnectionConfig
     configuration parameters to connect to vault,
     e.g. URL and access token
docstr_tok: ["Create","a","VaultClient","instance",".","Parameters","--","--","--","--","--","kms_connection_config",":","KmsConnectionConfig","configuration","parameters","to","connect","to","vault",",","e.g",".","URL","and","access","token"]
code: def __init__(self, kms_connection_config):
      """Create a VaultClient instance.
  
      Parameters
      ----------
      kms_connection_config : KmsConnectionConfig
         configuration parameters to connect to vault,
         e.g. URL and access token
      """
      pe.KmsClient.__init__(self)
      self.kms_url = (
          kms_connection_config.kms_instance_url
          + VaultClient.DEFAULT_TRANSIT_ENGINE
      )
      self.kms_connection_config = kms_connection_config
  
file_path: arrow/python/examples/parquet_encryption/sample_vault_kms_client.py
imports: import argparse
  import base64
  import os
  import requests
  import pyarrow
  import pyarrow.parquet
  import pyarrow.parquet.encryption
label_desc: Use image node_id 1 to create a new VaultClient object from inherited base classes: pe with example: obj = VaultClient(kms_connection_config)