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FindBullet
Try to find the Bullet physics engine
This module defines the following variables
  BULLET_FOUND - Was bullet found
BULLET_INCLUDE_DIRS - the Bullet include directories
BULLET_LIBRARIES - Link to this, by default it includes
                   all bullet components (Dynamics,
                   Collision, LinearMath, & SoftBody)
  This module accepts the following variables
  BULLET_ROOT - Can be set to bullet install path or Windows build path
  © 2000–2019 Kitware, Inc. and Contributors
Licensed under the BSD 3-clause License.
 https://cmake.org/cmake/help/v3.6/module/FindBullet.html