code: def _create_data(size, xp):
      float_data = {
          "data": xp.random.normal(size=size).astype("float32"),
          "levels": [-4.0, 4.0],
      }
      uint16_data = {
          "data": xp.random.randint(100, 4500, size=size).astype(
              "uint16"
          ),
          "levels": [250, 3000],
      }
      uint8_data = {
          "data": xp.random.randint(0, 255, size=size).astype("ubyte"),
          "levels": [20, 220],
      }
      c_map = xp.array([[-500.0, 255.0], [-255.0, 255.0], [0.0, 500.0]])
      uint8_lut = xp.zeros((256, 4), dtype="ubyte")
      for i in range(3):
          uint8_lut[:, i] = xp.clip(
              xp.linspace(c_map[i][0], c_map[i][1], 256), 0, 255
          )
      uint8_lut[:, 3] = 255
      uint16_lut = xp.zeros((2**16, 4), dtype="ubyte")
      for i in range(3):
          uint16_lut[:, i] = xp.clip(
              xp.linspace(c_map[i][0], c_map[i][1], 2**16), 0, 255
          )
      uint16_lut[:, 3] = 255
      return float_data, uint16_data, uint8_data, uint16_lut, uint8_lut
  
file_path: pyqtgraph/benchmarks/renderImageItem.py
imports: import numpy
  import pyqtgraph
label_desc: Use image node_id 7 for calling the _TimeSuite obj's underlying member method code with example usage: obj._create_data(size, xp) and returns: float_data,  uint16_data,  uint8_data,  uint16_lut,  uint8_lut