How to use the xonsh.ast.Load function in xonsh

def p_atom_expr_await(self, p):
        """atom_expr : await_tok atom trailer_list_opt"""
        p0 = self.apply_trailers(p[2], p[3])
        p1 = p[1]
        p0 = ast.Await(value=p0, ctx=ast.Load(), lineno=p1.lineno, col_offset=p1.lexpos)
        p[0] = p0

if isinstance(trailer, tuple):
                    trailer, arglist = trailer
                margs = [leader, trailer, gblcall, loccall]
                p0 = xonsh_call("__xonsh__.call_macro", margs, lineno=l, col=c)
            elif isinstance(trailer, str):
                if trailer == "?":
                    p0 = xonsh_help(leader, lineno=leader.lineno, col=leader.col_offset)
                elif trailer == "??":
                    p0 = xonsh_superhelp(
                        leader, lineno=leader.lineno, col=leader.col_offset
                    )
                else:
                    p0 = ast.Attribute(
                        value=leader,
                        attr=trailer,
                        ctx=ast.Load(),
                        lineno=leader.lineno,
                        col_offset=leader.col_offset,
                    )
            else:
                assert False
            leader = p0
        return p0

def p_atom_lparen(self, p):
        """atom : lparen_tok yield_expr_or_testlist_comp_opt RPAREN"""
        p1, p2 = p[1], p[2]
        p1, p1_tok = p1.value, p1
        if p2 is None:
            # empty container atom
            p0 = ast.Tuple(
                elts=[], ctx=ast.Load(), lineno=self.lineno, col_offset=self.col
            )
            p0._real_tuple = True
        elif isinstance(p2, ast.AST):
            p0 = p2
            p0._lopen_lineno, p0._lopen_col = p1_tok.lineno, p1_tok.lexpos
            p0._real_tuple = True
        elif len(p2) == 1 and isinstance(p2[0], ast.AST):
            p0 = p2[0]
            p0._lopen_lineno, p0._lopen_col = p1_tok.lineno, p1_tok.lexpos
        else:
            self.p_error(p)
        p[0] = p0

if p2:
            begins.extend([(x[0], x[1] + 1) for x in p2])
            ends = p2 + ends
        elts = []
        for beg, end in zip(begins, ends):
            s = self.source_slice(beg, end).strip()
            if not s:
                if len(begins) == 1:
                    break
                else:
                    msg = "empty macro arguments not allowed"
                    self._parse_error(msg, self.currloc(*beg))
            node = ast.Str(s=s, lineno=beg[0], col_offset=beg[1])
            elts.append(node)
        p0 = ast.Tuple(
            elts=elts, ctx=ast.Load(), lineno=p1.lineno, col_offset=p1.lexpos
        )
        p[0] = [p0]

def p_atom_name(self, p):
        """atom : name_tok"""
        p1 = p[1]
        p[0] = ast.Name(
            id=p1.value, ctx=ast.Load(), lineno=p1.lineno, col_offset=p1.lexpos
        )

def _envvar_getter_by_name(self, var, lineno=None, col=None):
        xenv = load_attribute_chain("__xonsh__.env", lineno=lineno, col=col)
        func = ast.Attribute(
            value=xenv, attr="get", ctx=ast.Load(), lineno=lineno, col_offset=col
        )
        return ast.Call(
            func=func,
            args=[
                ast.Str(s=var, lineno=lineno, col_offset=col),
                ast.Str(s="", lineno=lineno, col_offset=col),
            ],
            keywords=[],
            starargs=None,
            kwargs=None,
            lineno=lineno,
            col_offset=col,
        )

def call_split_lines(x, lineno=None, col=None):
    """Creates the AST node for calling the 'splitlines' attribute of an
    object, nominally a string.
    """
    return ast.Call(
        func=ast.Attribute(
            value=x, attr="splitlines", ctx=ast.Load(), lineno=lineno, col_offset=col
        ),
        args=[],
        keywords=[],
        starargs=None,
        kwargs=None,
        lineno=lineno,
        col_offset=col,
    )

def _envvar_by_name(self, var, lineno=None, col=None):
        """Looks up a xonsh variable by name."""
        xenv = load_attribute_chain("__xonsh__.env", lineno=lineno, col=col)
        idx = ast.Index(value=ast.Str(s=var, lineno=lineno, col_offset=col))
        return ast.Subscript(
            value=xenv, slice=idx, ctx=ast.Load(), lineno=lineno, col_offset=col
        )

if p2 is None:
            p0 = [p1]
        elif p2 == ",":
            p0 = [
                ast.Tuple(
                    elts=[p1],
                    ctx=ast.Load(),
                    lineno=p1.lineno,
                    col_offset=p1.col_offset,
                )
            ]
        else:
            p0 = [
                ast.Tuple(
                    elts=[p1] + p2,
                    ctx=ast.Load(),
                    lineno=p1.lineno,
                    col_offset=p1.col_offset,
                )
            ]
        p[0] = p0