Can't import net.minecraft.client.renderer.GlStatemanager

I was writing some render code for a custom mod that used the GlStateManager class for rotation and translation:

public void render(Entity entityIn, float limbSwing, float limbSwingAmount, float ageInTicks, float netHeadYaw, float headPitch,
				float scale) {
			GlStateManager.pushMatrix();
			GlStateManager.scaled(2.0F, 2.0F, 2.0F);
			GlStateManager.translated(0.0F, -0.5F, 0.0F);
			GlStateManager.rotate(limbSwingAmount, 0.0F, 1.0F, 0.0F);
			GlStateManager.translated(0.0F, 0.8F + ageInTicks, 0.0F);
			GlStateManager.rotate(60.0F, 0.7071F, 0.0F, 0.7071F);
			this.glass.render(scale);
			float f = 0.875F;
			GlStateManager.scaled(0.875F, 0.875F, 0.875F);
			GlStateManager.rotate(60.0F, 0.7071F, 0.0F, 0.7071F);
			GlStateManager.rotate(limbSwingAmount, 0.0F, 1.0F, 0.0F);
			this.glass.render(scale);
			GlStateManager.scaled(0.875F, 0.875F, 0.875F);
			GlStateManager.rotate(60.0F, 0.7071F, 0.0F, 0.7071F);
			GlStateManager.rotate(limbSwingAmount, 0.0F, 1.0F, 0.0F);
			this.cube.render(scale);
			GlStateManager.popMatrix();
		}

However, I have had errors importing net.minecraft.client.renderer.GlStateManager

I looked at the decompiled classes in the file viewer and noticed that the GlStateManager class is not listed. 

Is there any way to use this class in my code?