class_docstr: Provides context for a user acceptance test.
  
  Context consists of an environment suitable for run commands (used
  extensively by the uat) and the setting of Guild home to the
  global `GUILD_HOME` (required by in-process commands that use
  Guild home).
  
  Note that the UAT Guild home is, by default, local to the UAT
  workspace and not the current process Guild home.
code: def __init__(self):
      self._env = util.Env(
          {
              "COLUMNS": "999",
              "EXAMPLES": EXAMPLES,
              "GUILD_HOME": GUILD_HOME,
              "GUILD_PKG": GUILD_PKG,
              "GUILD_PKGDIR": guild.__pkgdir__,
              "LANG": os.getenv("LANG", "en_US.UTF-8"),
              "REQUIREMENTS_PATH": REQUIREMENTS_PATH,
              "TEMP": TEMP,
              "WORKSPACE": WORKSPACE,
          }
      )
      self._guild_home = config.SetGuildHome(GUILD_HOME)
  
imports: import fnmatch
  import os
  import re
  import sys
  import tempfile
  import guild
  from guild import _test
  from guild import config
  from guild import pip_util
  from guild import util
label_desc: Use image node_id 1 to create a new UATContext object  with example: obj = UATContext()