What does "Velocimacro with a Body" mean?

Hi,
 
            I am new to
Velocity and I am wondering what "Velocimacro with a Body" means?
Here, I am referring to the description in http://velocity.apache.org/engine/releases/velocity-1.7/vtl-reference-guide.html#amacro_-_Allows_users_to_define_a_Velocimacro_VM_a_repeated_segment_of_a_VTL_template_as_required
 
            I thought
all Velocimacros had bodies, just like all non-trivial functions in C or Java
have bodies. I attempted the use the above suggestion given in the URL and it did not
work.
 
I attempted the following in my Global Library: 
 
#macro(query_url $query_param) 
    q=$query_param 
#end 
 
#macro(trim) 
$!bodyContent.trim() 
#end  
 
According to the above URL, in my template, I called this
using: 
 
#@trim()#query_url("sometext")#end 
 
 
The result seems to be: 
            q=sometext 
 
i.e. there are spaces in the front that I don't like.
(Depending on the format you are looking at, these preceeding spaces might be
deleted, but they appear in the rendered results.) Any ideas what I am doing
wrong?
 
Thank you in advance, 
O. O.