class_docstr: Metrics Plugin for TensorBoard.
docstr: Gets the image data for a blob key.
  
  Args:
      ctx: A `tensorboard.context.RequestContext` value.
      blob_key: a string identifier for a DataProvider blob.
  
  Returns:
      A tuple containing:
        data: a raw bytestring of the requested image's contents.
        content_type: a string HTTP content type.
docstr_tok: ["Gets","the","image","data","for","a","blob","key",".","Args",":","ctx",":","A","`","tensorboard.context.RequestContext","`","value",".","blob_key",":","a","string","identifier","for","a","DataProvider","blob",".","Returns",":","A","tuple","containing",":","data",":","a","raw","bytestring","of","the","requested","image","'s","contents",".","content_type",":","a","string","HTTP","content","type","."]
code: def _image_data_impl(self, ctx, blob_key):
      """Gets the image data for a blob key.
  
      Args:
          ctx: A `tensorboard.context.RequestContext` value.
          blob_key: a string identifier for a DataProvider blob.
  
      Returns:
          A tuple containing:
            data: a raw bytestring of the requested image's contents.
            content_type: a string HTTP content type.
      """
      data = self._data_provider.read_blob(ctx, blob_key=blob_key)
      image_type = imghdr.what(None, data)
      content_type = _IMGHDR_TO_MIMETYPE.get(
          image_type, _DEFAULT_IMAGE_MIMETYPE
      )
      return (data, content_type)
  
imports: import collections
  import imghdr
  import json
  from werkzeug import wrappers
  from tensorboard import errors
  from tensorboard import plugin_util
  from tensorboard.backend import http_util
  from tensorboard.data import provider
  from tensorboard.plugins import base_plugin
  from tensorboard.plugins.histogram import metadata
  from tensorboard.plugins.image import metadata
  from tensorboard.plugins.metrics import metadata
  from tensorboard.plugins.scalar import metadata
label_desc: Use image node_id 19 for calling the MetricsPlugin obj's underlying member method code with example usage: obj._image_data_impl(ctx, blob_key) and returns: data,  content_type