code: public Matrix3x2d set(Matrix3x2dc m) {
          if (m instanceof Matrix3x2d) {
              MemUtil.INSTANCE.copy((Matrix3x2d) m, this);
          } else {
              setMatrix3x2dc(m);
          }
          return this;
      }
docs: Set the elements of this matrix to the ones in <code>m</code>.
  
  @param m
  the matrix to copy the elements from
  @return this